Inital Release:          OTP 29.0
Git Tag:                 OTP-29.0
Date:                    2026-04-15
Trouble Report Id:       OTP-16607, OTP-19587, OTP-19611, OTP-19643,
                         OTP-19663, OTP-19672, OTP-19695, OTP-19708,
                         OTP-19709, OTP-19713, OTP-19734, OTP-19744,
                         OTP-19747, OTP-19750, OTP-19751, OTP-19763,
                         OTP-19766, OTP-19783, OTP-19784, OTP-19785,
                         OTP-19786, OTP-19793, OTP-19800, OTP-19801,
                         OTP-19807, OTP-19809, OTP-19811, OTP-19815,
                         OTP-19822, OTP-19826, OTP-19834, OTP-19838,
                         OTP-19842, OTP-19853, OTP-19858, OTP-19866,
                         OTP-19874, OTP-19882, OTP-19887, OTP-19898,
                         OTP-19903, OTP-19906, OTP-19910, OTP-19912,
                         OTP-19917, OTP-19918, OTP-19919, OTP-19921,
                         OTP-19922, OTP-19925, OTP-19927, OTP-19932,
                         OTP-19933, OTP-19934, OTP-19935, OTP-19936,
                         OTP-19938, OTP-19942, OTP-19943, OTP-19949,
                         OTP-19956, OTP-19960, OTP-19963, OTP-19964,
                         OTP-19965, OTP-19966, OTP-19968, OTP-19969,
                         OTP-19975, OTP-19980, OTP-19982, OTP-19991,
                         OTP-19995, OTP-19996, OTP-19997, OTP-20001,
                         OTP-20002, OTP-20003, OTP-20004, OTP-20010,
                         OTP-20013, OTP-20015, OTP-20016, OTP-20017,
                         OTP-20019, OTP-20020, OTP-20023, OTP-20025,
                         OTP-20026, OTP-20028, OTP-20029, OTP-20030,
                         OTP-20031, OTP-20032, OTP-20034, OTP-20035,
                         OTP-20036, OTP-20045, OTP-20048, OTP-20054,
                         OTP-20055, OTP-20059, OTP-20061, OTP-20066,
                         OTP-20069, OTP-20070, OTP-20071, OTP-20072,
                         OTP-20073, OTP-20076, OTP-20077, OTP-20078,
                         OTP-20079, OTP-20080, OTP-20088, OTP-20090,
                         OTP-20092, OTP-20095, OTP-20099
Seq num:                 GH-10071, GH-10125, GH-10151, GH-10214,
                         GH-10260, GH-10341, GH-10345, GH-10557,
                         GH-10650, GH-10807, GH-8569, GH-8841,
                         GH-8993, GH-9822, OTP-16608, OTP-19652,
                         OTP-19775, OTP-19779, OTP-19827, PR-10013,
                         PR-10033, PR-10078, PR-10114, PR-10115,
                         PR-10126, PR-10134, PR-10144, PR-10145,
                         PR-10161, PR-10166, PR-10168, PR-10187,
                         PR-10189, PR-10193, PR-10195, PR-10197,
                         PR-10202, PR-10207, PR-10230, PR-10234,
                         PR-10243, PR-10253, PR-10259, PR-10269,
                         PR-10276, PR-10277, PR-10281, PR-10304,
                         PR-10338, PR-10348, PR-10372, PR-10382,
                         PR-10387, PR-10417, PR-10421, PR-10422,
                         PR-10426, PR-10433, PR-10449, PR-10453,
                         PR-10478, PR-10510, PR-10511, PR-10514,
                         PR-10519, PR-10524, PR-10532, PR-10549,
                         PR-10554, PR-10556, PR-10564, PR-10568,
                         PR-10571, PR-10573, PR-10578, PR-10579,
                         PR-10580, PR-10585, PR-10592, PR-10598,
                         PR-10601, PR-10614, PR-10615, PR-10617,
                         PR-10619, PR-10626, PR-10642, PR-10646,
                         PR-10647, PR-10653, PR-10656, PR-10674,
                         PR-10710, PR-10718, PR-10730, PR-10735,
                         PR-10739, PR-10753, PR-10754, PR-10755,
                         PR-10770, PR-10782, PR-10783, PR-10801,
                         PR-10804, PR-10805, PR-10814, PR-10817,
                         PR-10818, PR-10819, PR-10820, PR-10821,
                         PR-10824, PR-10830, PR-10836, PR-10838,
                         PR-10839, PR-10870, PR-10892, PR-10894,
                         PR-10910, PR-10938, PR-10948, PR-10949,
                         PR-10950, PR-10951, PR-10958, PR-10962,
                         PR-10965, PR-10969, PR-10970, PR-10979,
                         PR-10986, PR-10998, PR-11004, PR-11010,
                         PR-7118, PR-7315, PR-9115, PR-9125, PR-9134,
                         PR-9153, PR-9209, PR-9223, PR-9315, PR-9374,
                         PR-9475, PR-9712, PR-9814, PR-9864, PR-9866,
                         PR-9894, PR-9899, PR-9934, PR-9940, PR-9984
System:                  OTP
Release:                 29
Application:             asn1-5.5, common_test-1.31, compiler-10.0,
                         crypto-5.9, debugger-7.0, dialyzer-6.0,
                         diameter-2.7, edoc-1.5, eldap-1.3,
                         erl_interface-5.7, erts-17.0, et-1.8,
                         eunit-2.11, ftp-1.2.5, inets-9.7,
                         jinterface-1.16, kernel-11.0, megaco-4.9,
                         mnesia-4.26, observer-2.19, odbc-2.17,
                         os_mon-2.12, parsetools-2.8, public_key-1.21,
                         reltool-1.1, runtime_tools-2.4, sasl-4.4,
                         snmp-5.20.3, ssh-6.0, ssl-11.6, stdlib-8.0,
                         syntax_tools-4.1, tftp-1.3, tools-4.2,
                         wx-2.6, xmerl-2.2
Predecessor:             OTP

Check out the git tag OTP-29.0, and build a full OTP system including documentation.

HIGHLIGHTS

The JIT now generates better code for matching or creating binaries with multiple little-endian segments.
Own Id: OTP-19747
Application(s): erts
Related Id(s): PR-10126
In the documentation for the compile module, a section has been added with recommendations for implementors of languages running on the BEAM. Documentation has also been added for the to_abstr, to_exp, and from_abstr options.
The documentation for erlc now lists .abstr as one of the supported options.
When compiling with the to_abstr option, the resulting .abstr file now retains any -doc attributes present in the source code.
Own Id: OTP-19784
Application(s): compiler, erts
Related Id(s): PR-10230, PR-10234
Native records as described in EEP-79 has been implemented.
A native record is a data structure similar to the traditional tuple-based records, except that is a true data type.
Native records are considered experimental in Erlang/OTP 29 and possibly also in Erlang/OTP 30, meaning that their behavior may change, potentially requiring updates to applications that use them.
Own Id: OTP-19785
Application(s): compiler, debugger, dialyzer, erts, stdlib
Related Id(s): PR-10617
The guard BIF is_integer/3 has been added. It follows the design of the original EEP-16, only changing the name from is_between to is_integer. This BIF takes in 3 parameters, Term, LowerBound, and UpperBound.
It returns true if Term, LowerBound, and UpperBound are all integers, and LowerBound =< Term =< UpperBound; otherwise, it returns false.
Example:
```
1> I = 42.
2> is_integer(I, 0, 100).
true
```
Own Id: OTP-19809
Application(s): compiler, dialyzer, erts
Related Id(s): PR-10276
There are new functions for random permutation of a list: rand:shuffle/1 and rand:shuffle_s/2. They are inspired by a suggestion and discussion on ErlangForums.
Own Id: OTP-19826
Application(s): stdlib
Related Id(s): PR-10281
In the default code path for the Erlang system, the current working directory (.) is now in the last position instead of the first.
Own Id: OTP-19842
Application(s): erts, kernel
*** POTENTIAL INCOMPATIBILITY ***
Function application is now left associative. That means one can now write:
```
f(X)(Y)
```
instead of:
```
(f(X))(Y)
```
Own Id: OTP-19866
Application(s): compiler
Related Id(s): PR-9223
The old-style type tests in guards (integer, atom, and so on) have been scheduled for removal in Erlang/OTP 30. They have been deprecated for a long time.
Own Id: OTP-19887
Application(s): otp
Related Id(s): PR-10417
There will now be a warning when exporting variables out of a subexpression. For example:
```
case file:open(File, AllOpts = [write,{encoding,utf8}]) of
    {ok,Fd} ->
        {Fd,AllOpts}
end
```
To avoid the warning, this can be rewritten to:
```
AllOpts = [write,{encoding,utf8}],
case file:open(File, AllOpts) of
    {ok,Fd} ->
        {Fd,AllOpts}
end
```
The warning can be suppressed by giving option nowarn_export_var_subexpr to the compiler.
Own Id: OTP-19898
Application(s): compiler, stdlib
Related Id(s): PR-9134
By default, the compiler will now warn for uses of the and and or operators.
This warning can be suppressed using the nowarn_obsolete_bool_op compiler option.
Own Id: OTP-19918
Application(s): compiler
Related Id(s): PR-9115
graph is a new module that is a functional equivalent of the digraph and digraph_utils modules.
Own Id: OTP-19922
Application(s): stdlib
Related Id(s): PR-10532

Before Erlang/OTP 29, attempting to bind variables in a comprehension would compile successfully but fail at runtime. Example:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
* exception error: bad filter 2614250

In Erlang/OTP 29, attempting to bind a variable in a comprehension will fail by default:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
* 5:14: matches using '=' are not allowed in comprehension qualifiers
unless the experimental 'compr_assign' language feature is enabled.
With 'compr_assign' enabled, a match 'P = E' will behave as a
strict generator 'P <-:- [E]'."

However, this example will work as expected if the compr_assign feature is enabled when starting the runtime system:

$ erl -enable-feature compr_assign
. . .
1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
[2614250]

Here is another example how compr_assign can be used:

-module(example).
-feature(compr_assign, enable).
-export([cat/1]).

cat(Files) ->
    [Char || F <- Files,
             {ok, Bin} = file:read_file(F),
             Char <- unicode:characters_to_list(Bin)].

Own Id: OTP-19927
Application(s): compiler, stdlib
Related Id(s): PR-9153

*** POTENTIAL INCOMPATIBILITY ***

There will now be a warning when using the catch operator, which has been deprecated for a long time.
It is recommended to instead use try...catch...end but is also possible to disable the warning by using the nowarn_deprecated_catch option.
Own Id: OTP-19938
Application(s): compiler, stdlib
Related Id(s): PR-10421
Multi-valued comprehensions according to EEP 78 has been implemented.
Example:
```
> [I, -I || I <- lists:seq(1, 5)].
[1,-1,2,-2,3,-3,4,-4,5,-5]
```
Own Id: OTP-19942
Application(s): compiler, debugger, stdlib, syntax_tools
Related Id(s): PR-9374
There will now be a warning for matches that unify constructors, such as the following:
```
m({a,B} = {Y,Z}) -> . . .
```
Such a match can be rewritten to:
```
m({a=Y,B=B}) -> . . .
```
The compiler option nowarn_match_alias_pats can be used to disable the warning.
Own Id: OTP-19943
Application(s): compiler, stdlib
Related Id(s): PR-10433
There is no longer a 32-bit Erlang/OTP build for Windows.
Own Id: OTP-19960
Application(s): otp
While the iteration order for maps is undefined, it is now guaranteed that all ways of iterating over maps provides the elements in the same order. That is, all of the following ways of iterating will produce the elements in the same order:
- maps:keys/1
- maps:values/1
- maps:to_list/1
- maps:to_list(maps:iterator(M))
- Map comprehension: [{K,V} || K := V <- M]
Own Id: OTP-19963
Application(s): erts
Related Id(s): PR-10626
The default key exchange algorithm is now mlkem768x25519-sha256, a hybrid quantum-resistant algorithm combining ML-KEM-768 with X25519. This provides protection against both classical and quantum computer attacks while maintaining backward compatibility through automatic fallback to other algorithms when peers don't support it.
Own Id: OTP-19965
Application(s): ssh
Related Id(s): PR-10656
*** POTENTIAL INCOMPATIBILITY ***
The compiler now generates more efficient code for map comprehensions with constant values that don't depend on the generator, such as the following:
```
#{K => 42} || K <- List}.
#{K => X || K <- List}.
#{K => {X, Y} || K <- List}.
```
Own Id: OTP-19968
Application(s): compiler
Related Id(s): PR-10646
The SSH daemon now defaults to disabled for shell and exec services, implementing the "secure by default" principle. This prevents authenticated users from executing arbitrary Erlang code unless explicitly configured.
Applications requiring shell or exec functionality must now explicitly enable:
```
  %% Enable Erlang shell
  ssh:daemon(Port, [{shell, {shell, start, []}} | Options])

  %% Enable Erlang term evaluation via exec
  ssh:daemon(Port, [{exec, erlang_eval} | Options])

  %% Restore complete old behavior
  ssh:daemon(Port, [{shell, {shell, start, []}},
                    {exec, erlang_eval}
                    | Options])
```
Own Id: OTP-19969
Application(s): ssh
Related Id(s): PR-10970
*** POTENTIAL INCOMPATIBILITY ***
The odbc application is now deprecated and is planned to be removed in Erlang/OTP 30.
The ftp and ct_ftp modules are now deprecated and are planned to be removed in Erlang/OTP 30.
Own Id: OTP-19980
Application(s): ftp, odbc
Related Id(s): PR-10804
The array module have been extended with several new functions. The internal representation have been changed to allow the new functionality and optimizations. Arrays serialized with term_to_binary/1 in previous releases are not compatible.
Own Id: OTP-20004
Application(s): stdlib
Related Id(s): PR-10578
*** POTENTIAL INCOMPATIBILITY ***
Added support for socket functions recvmmsg() and sendmmsg().
Own Id: OTP-20015
Application(s): erts, kernel
Related Id(s): PR-10564
m:erl_tar will use less memory when extracting large tar entries to disk. Instead of reading each tar entry into memory, erl_tar will now stream data in chunks of 64KB. The chunk size is settable using the new {chunks,ChunkSize} option.
The new {max_size,Size} option will set a limit on the total size of extracted data to protect against filling up the disk.
Checking of symlinks has been improved. Some symlinks that were safe (such as dir/link -> ../file) used to be rejected.
Own Id: OTP-20023
Application(s): stdlib
Related Id(s): PR-10814, PR-10818, PR-10821
Added a new module called io_ansi that allows the user to emit Virtual Terminal Sequences (a.k.a. ANSI sequences) to the terminal in order to add colors/styling to text or create fully-fledged terminal applications.
io_ansi uses the local terminfo database in order to be as cross-platform compatible as possible.
It also works across nodes so that if functions on a remote node call io_ansi:fwrite/1 it will use the destination terminal's terminfo database to determine which sequences to emit. In practice, this means that you can call functions in a remote shell session that use io_ansi and it will properly detect the terminal sequences the target terminal can handle and will print using them correctly.
Own Id: OTP-20028
Application(s): kernel, stdlib
Related Id(s): PR-9940
The ignore_xref attribute has been handled as a post-analysis filter by build tools such as Rebar3. In this release, xref itself does the filtering, ensuring that all tooling that calls xref for any purpose can rely on these declarations to just work.
Own Id: OTP-20032
Application(s): tools
Related Id(s): PR-10592
New in this release is ct_doctest, a module that allows the user to test documentation examples in Erlang module docs and documentation files.
ct_doctest allows you to:
- Test code examples using shell syntax and their returns
- Test code examples that should fail
- Write example modules that are compiled and available in shell examples
- Plugin other documentation parsing engines so that examples in, for example, edoc, asciidoc, and others can also be tested.
See the documentation for more details.
Own Id: OTP-20034
Application(s): common_test
Related Id(s): PR-10824, PR-9315
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Application(s): asn1, common_test, compiler, crypto, debugger, dialyzer, diameter, edoc, eunit, inets, kernel, megaco, mnesia, observer, odbc, os_mon, otp, parsetools, public_key, reltool, runtime_tools, sasl, ssh, ssl, stdlib, syntax_tools, tftp, tools, wx, xmerl
Related Id(s): PR-10839
Post quantum hybrid algorithm x25519mlkem768 is now the most preferred key exchange group in the default configuration.
Post-quantum hybrid algorithms secp384r1mlkem1024 and secp256r1mlkem768 are supported but have to be configured. The same goes for the plain post-quantum algorithms mlkem1024, mlkem768, and mlkem512.
The most preferred signature algorithms are now post-quantum algorithms ML-DSA and SLH-DSA if such certs are available in the configuration.
All these algorithms where available in OTP-28.4 but none of them preferred and some of them changed default status.
Own Id: OTP-20070
Application(s): ssl
Related Id(s): PR-10949
*** POTENTIAL INCOMPATIBILITY ***
The json module now encodes and decodes quoted strings faster. Improvements of up to 55 percent has been measured when decoding JSON data with long strings.
The string:length/1, string:slice/2, and string:slice/3 functions have been optimized. For some strings, they can be up to twice as fast.
Own Id: OTP-20072
Application(s): stdlib
Related Id(s): PR-10938, PR-10948
The SFTP subsystem is no longer enabled by default when starting an SSH daemon. To enable it, add the subsystems option explicitly:
```
ssh:daemon(Port, [{subsystems, [ssh_sftpd:subsystem_spec([])]} | Options])
```
Own Id: OTP-20078
Application(s): ssh
Related Id(s): PR-10970
*** POTENTIAL INCOMPATIBILITY ***

POTENTIAL INCOMPATIBILITIES

Fixed (inet) module selection when calling (gen_tcp) listen and connect and (gen_udp) open. Depending on the order of the options, the module option (tcp_module or udp_module) was sometimes ignored.
Own Id: OTP-19695
Application(s): kernel
Related Id(s): GH-9822, PR-10013
ssh:stop_deamon now uses supervisor:stop for shutting down daemons. With this change, the scenario when ssh:stop_daemon is called for a non-existing process results in calling process exiting. Previously an error tuple was returned (which was not documented).
Own Id: OTP-19801
Application(s): ssh
Related Id(s): PR-10253
The mnesia_registry module has been removed.
Own Id: OTP-19807
Application(s): mnesia
Related Id(s): PR-7315
In the default code path for the Erlang system, the current working directory (.) is now in the last position instead of the first.
Own Id: OTP-19842
Application(s): erts, kernel
*** HIGHLIGHT ***

Before Erlang/OTP 29, attempting to bind variables in a comprehension would compile successfully but fail at runtime. Example:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
* exception error: bad filter 2614250

In Erlang/OTP 29, attempting to bind a variable in a comprehension will fail by default:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
* 5:14: matches using '=' are not allowed in comprehension qualifiers
unless the experimental 'compr_assign' language feature is enabled.
With 'compr_assign' enabled, a match 'P = E' will behave as a
strict generator 'P <-:- [E]'."

However, this example will work as expected if the compr_assign feature is enabled when starting the runtime system:

$ erl -enable-feature compr_assign
. . .
1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
[2614250]

Here is another example how compr_assign can be used:

-module(example).
-feature(compr_assign, enable).
-export([cat/1]).

cat(Files) ->
    [Char || F <- Files,
             {ok, Bin} = file:read_file(F),
             Char <- unicode:characters_to_list(Bin)].

Own Id: OTP-19927
Application(s): compiler, stdlib
Related Id(s): PR-9153

*** HIGHLIGHT ***

The default key exchange algorithm is now mlkem768x25519-sha256, a hybrid quantum-resistant algorithm combining ML-KEM-768 with X25519. This provides protection against both classical and quantum computer attacks while maintaining backward compatibility through automatic fallback to other algorithms when peers don't support it.
Own Id: OTP-19965
Application(s): ssh
Related Id(s): PR-10656
*** HIGHLIGHT ***
The SSH daemon now defaults to disabled for shell and exec services, implementing the "secure by default" principle. This prevents authenticated users from executing arbitrary Erlang code unless explicitly configured.
Applications requiring shell or exec functionality must now explicitly enable:
```
  %% Enable Erlang shell
  ssh:daemon(Port, [{shell, {shell, start, []}} | Options])

  %% Enable Erlang term evaluation via exec
  ssh:daemon(Port, [{exec, erlang_eval} | Options])

  %% Restore complete old behavior
  ssh:daemon(Port, [{shell, {shell, start, []}},
                    {exec, erlang_eval}
                    | Options])
```
Own Id: OTP-19969
Application(s): ssh
Related Id(s): PR-10970
*** HIGHLIGHT ***
Changed ets:update_counter/4 and ets:update_element/4 to always reject default tuples smaller than the keypos of the table. Such keyless tuples are now rejected even if the key exists in the table and the default tuple would not be used. This is a subtle semantic change but is a nicer behavior for development and testing as it will detect faulty default tuple arguments earlier.
Own Id: OTP-19975
Application(s): erts
Related Id(s): PR-10674
Added explicit size validation guards for pre-authentication SSH messages to improve defense-in-depth against DoS attacks. Messages now have per-field size limits based on RFC specifications:
- Transport layer messages (DISCONNECT, IGNORE, DEBUG)
- Key exchange messages (DH, ECDH, DH-GEX)
- Service request messages (SERVICE_REQUEST, SERVICE_ACCEPT, EXT_INFO)
This change enhances the existing 256KB global packet size limit with granular per-message validation. Compliant implementations are not affected.
Own Id: OTP-19995
Application(s): ssh
Related Id(s): PR-10739
The array module have been extended with several new functions. The internal representation have been changed to allow the new functionality and optimizations. Arrays serialized with term_to_binary/1 in previous releases are not compatible.
Own Id: OTP-20004
Application(s): stdlib
Related Id(s): PR-10578
*** HIGHLIGHT ***
The SFTP subsystem root option now properly rejects relative paths at daemon startup. Previously, relative paths would cause unpredictable behavior as file operations resolved relative to the Erlang VM's current working directory. The option now requires an absolute path or empty string.
Own Id: OTP-20019
Application(s): ssh
Related Id(s): PR-10820
The gb_sets:from_ordset/1 and gb_trees:from_orddict/1 functions would trust their inputs. If the input contained duplicates or was not properly sorted, the resulting gb_set or gb_tree would be invalid, and any number of interesting problems could occur.
In this release, these functions will raise an exception if their input is not valid. That could mean that incorrect programs that seemed to work could now stop working altogether.
There is also a new gb_trees:from_list/1 function for directly creating a gb_tree from a list.
Own Id: OTP-20061
Application(s): stdlib
Related Id(s): PR-10910
Post quantum hybrid algorithm x25519mlkem768 is now the most preferred key exchange group in the default configuration.
Post-quantum hybrid algorithms secp384r1mlkem1024 and secp256r1mlkem768 are supported but have to be configured. The same goes for the plain post-quantum algorithms mlkem1024, mlkem768, and mlkem512.
The most preferred signature algorithms are now post-quantum algorithms ML-DSA and SLH-DSA if such certs are available in the configuration.
All these algorithms where available in OTP-28.4 but none of them preferred and some of them changed default status.
Own Id: OTP-20070
Application(s): ssl
Related Id(s): PR-10949
*** HIGHLIGHT ***
The old Tcl-based implementation of erl_errno_id() has been replaced by our own implementation now supporting more errno values on modern operating systems. It now also returns the string "errno_<ERRNO_INTEGER>" corresponding to the integer given as argument if the errno integer is unknown instead of as previously just return the string "unknown".
The result of erl_errno_id() is often converted into an atom and passed as an error from a driver or a NIF.
Own Id: OTP-20076
Application(s): erts
Related Id(s): PR-10958, PR-10969
The SFTP subsystem is no longer enabled by default when starting an SSH daemon. To enable it, add the subsystems option explicitly:
```
ssh:daemon(Port, [{subsystems, [ssh_sftpd:subsystem_spec([])]} | Options])
```
Own Id: OTP-20078
Application(s): ssh
Related Id(s): PR-10970
*** HIGHLIGHT ***
Always use secure renegotiation for TLS-1.2 specified in RFC 5746 from 2010. Interoperability fallback option should no longer be needed.
Own Id: OTP-20080
Application(s): ssl
Related Id(s): PR-10979
The erlang:suspend_process/1 and erlang:suspend_process/2 BIFs now also suspend BIF timers that will send messages to the process if the timer was created using the PID of the process as destination. Timers created using registered names are not affected.
Own Id: OTP-20095
Application(s): erts
Related Id(s): PR-10619, PR-11004

OTP-29.0

Improvements and New Features

Vendor dependencies and OpenVEX statements in the otp repository is now scanned for vulnerabilities. It is verified that OTP security issues reported at Github exist in the published OpenVEX statements, and issues are automatically opened in the otp repository if vendor vulnerabilities are detected.
Own Id: OTP-19763
Related Id(s): PR-10145, PR-10166, PR-10168, PR-10189, PR-10193, PR-10195, PR-10197, PR-10202, OTP-19652, OTP-19775, OTP-19779
Documentation about how to validate the SBOM using sigstore has been added.
Own Id: OTP-19766
Related Id(s): GH-10151, PR-10187
The old-style type tests in guards (integer, atom, and so on) have been scheduled for removal in Erlang/OTP 30. They have been deprecated for a long time.
Own Id: OTP-19887
Related Id(s): PR-10417
*** HIGHLIGHT ***
Removed the undocumented dyn_erl utility.
Own Id: OTP-19933
Related Id(s): PR-10573
There is no longer a 32-bit Erlang/OTP build for Windows.
Own Id: OTP-19960
*** HIGHLIGHT ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***
The Upcoming Potential Incompatibilities page has been updated to note that in Erlang/OTP 30, erlang:fun_info(Fun, pid) will no longer retrieve a pid, but will raise a badarg exception.
Own Id: OTP-20092
Related Id(s): PR-10998

asn1-5.5

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of asn1-5.5

erts-14.0, kernel-9.0, stdlib-5.0

common_test-1.31

Fixed Bugs and Malfunctions

Improved support for QuickCheck when writing property tests.
Own Id: OTP-20010
Related Id(s): PR-10783

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
'EXIT' messages are now formatted in the same way as badmatch errors.
Own Id: OTP-19910
Related Id(s): PR-10277
Error notifications now contain the name of the source file in which the error occurred.
Own Id: OTP-19925
Related Id(s): GH-10260, PR-10269
New in this release is ct_doctest, a module that allows the user to test documentation examples in Erlang module docs and documentation files.
ct_doctest allows you to:
- Test code examples using shell syntax and their returns
- Test code examples that should fail
- Write example modules that are compiled and available in shell examples
- Plugin other documentation parsing engines so that examples in, for example, edoc, asciidoc, and others can also be tested.
See the documentation for more details.
Own Id: OTP-20034
Related Id(s): PR-10824, PR-9315
*** HIGHLIGHT ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of common_test-1.31

compiler-10.0, crypto-4.5, debugger-4.1, erts-7.0, ftp-1.0, inets-6.0, kernel-11.0, observer-2.1, runtime_tools-1.8.16, sasl-2.5, snmp-5.1.2, ssh-4.0, stdlib-8.0, syntax_tools-1.7, tools-3.2, xmerl-1.3.8

compiler-10.0

Fixed Bugs and Malfunctions

For a function such as the following:
```
bar(S0) ->
    S1 = setelement(8, S0, a),
    S2 = setelement(7, S1, b),
    setelement(5, S2, c).
```
the compiler would keep all of the calls to setelement/3 and emit extra unnecessary set_tuple_element instructions.
This has been corrected so that the compiler will never emit code that uses the set_tuple_element instruction. In a future release, support for the set_tuple_element will be removed from the runtime system.
Own Id: OTP-19751
Related Id(s): GH-10125, PR-10144
beam_lib:strip/1 will now retain the Beam debug information chunk produced by the beam_debug_info option. The chunk will also be retained when combing the beam_debug_info option with the undocumented slim option.
The runtime system will no longer crash when attempting to load modules that have been compiled with beam_debug_info but lack the actual Beam debug info chunk.
Own Id: OTP-19991
Related Id(s): GH-10557, PR-10735

Improvements and New Features

In comprehensions, a generator that builds a list with a single element will now be optimized to avoid building and matching the list. Example:
```
[H || E <- List, H <- [erlang:phash2(E)], H rem 10 =:= 0]
```
Own Id: OTP-19672
Related Id(s): PR-9934
In the documentation for the compile module, a section has been added with recommendations for implementors of languages running on the BEAM. Documentation has also been added for the to_abstr, to_exp, and from_abstr options.
The documentation for erlc now lists .abstr as one of the supported options.
When compiling with the to_abstr option, the resulting .abstr file now retains any -doc attributes present in the source code.
Own Id: OTP-19784
Related Id(s): PR-10230, PR-10234
*** HIGHLIGHT ***
Native records as described in EEP-79 has been implemented.
A native record is a data structure similar to the traditional tuple-based records, except that is a true data type.
Native records are considered experimental in Erlang/OTP 29 and possibly also in Erlang/OTP 30, meaning that their behavior may change, potentially requiring updates to applications that use them.
Own Id: OTP-19785
Related Id(s): PR-10617
*** HIGHLIGHT ***
The guard BIF is_integer/3 has been added. It follows the design of the original EEP-16, only changing the name from is_between to is_integer. This BIF takes in 3 parameters, Term, LowerBound, and UpperBound.
It returns true if Term, LowerBound, and UpperBound are all integers, and LowerBound =< Term =< UpperBound; otherwise, it returns false.
Example:
```
1> I = 42.
2> is_integer(I, 0, 100).
true
```
Own Id: OTP-19809
Related Id(s): PR-10276
*** HIGHLIGHT ***
Function application is now left associative. That means one can now write:
```
f(X)(Y)
```
instead of:
```
(f(X))(Y)
```
Own Id: OTP-19866
Related Id(s): PR-9223
*** HIGHLIGHT ***
There will now be a warning when exporting variables out of a subexpression. For example:
```
case file:open(File, AllOpts = [write,{encoding,utf8}]) of
    {ok,Fd} ->
        {Fd,AllOpts}
end
```
To avoid the warning, this can be rewritten to:
```
AllOpts = [write,{encoding,utf8}],
case file:open(File, AllOpts) of
    {ok,Fd} ->
        {Fd,AllOpts}
end
```
The warning can be suppressed by giving option nowarn_export_var_subexpr to the compiler.
Own Id: OTP-19898
Related Id(s): PR-9134
*** HIGHLIGHT ***
By default, the compiler will now warn for uses of the and and or operators.
This warning can be suppressed using the nowarn_obsolete_bool_op compiler option.
Own Id: OTP-19918
Related Id(s): PR-9115
*** HIGHLIGHT ***

Before Erlang/OTP 29, attempting to bind variables in a comprehension would compile successfully but fail at runtime. Example:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
* exception error: bad filter 2614250

In Erlang/OTP 29, attempting to bind a variable in a comprehension will fail by default:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
* 5:14: matches using '=' are not allowed in comprehension qualifiers
unless the experimental 'compr_assign' language feature is enabled.
With 'compr_assign' enabled, a match 'P = E' will behave as a
strict generator 'P <-:- [E]'."

However, this example will work as expected if the compr_assign feature is enabled when starting the runtime system:

$ erl -enable-feature compr_assign
. . .
1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
[2614250]

Here is another example how compr_assign can be used:

-module(example).
-feature(compr_assign, enable).
-export([cat/1]).

cat(Files) ->
    [Char || F <- Files,
             {ok, Bin} = file:read_file(F),
             Char <- unicode:characters_to_list(Bin)].

Own Id: OTP-19927
Related Id(s): PR-9153

*** HIGHLIGHT ***

*** POTENTIAL INCOMPATIBILITY ***

There will now be a warning when using the catch operator, which has been deprecated for a long time.
It is recommended to instead use try...catch...end but is also possible to disable the warning by using the nowarn_deprecated_catch option.
Own Id: OTP-19938
Related Id(s): PR-10421
*** HIGHLIGHT ***
Multi-valued comprehensions according to EEP 78 has been implemented.
Example:
```
> [I, -I || I <- lists:seq(1, 5)].
[1,-1,2,-2,3,-3,4,-4,5,-5]
```
Own Id: OTP-19942
Related Id(s): PR-9374
*** HIGHLIGHT ***
There will now be a warning for matches that unify constructors, such as the following:
```
m({a,B} = {Y,Z}) -> . . .
```
Such a match can be rewritten to:
```
m({a=Y,B=B}) -> . . .
```
The compiler option nowarn_match_alias_pats can be used to disable the warning.
Own Id: OTP-19943
Related Id(s): PR-10433
*** HIGHLIGHT ***
The compiler now generates more efficient code for map comprehensions with constant values that don't depend on the generator, such as the following:
```
#{K => 42} || K <- List}.
#{K => X || K <- List}.
#{K => {X, Y} || K <- List}.
```
Own Id: OTP-19968
Related Id(s): PR-10646
*** HIGHLIGHT ***
Compilation times of modules with a huge number of calls to element/2 has been improved.
Own Id: OTP-20020
Related Id(s): GH-10807, PR-10819
The format of the debug information stored by the beam_debug_info option (used by the edb debugger) has been updated to more easily extendible and to contain more information about call targets. (See the linked PR for more details.)
Own Id: OTP-20048
Related Id(s): PR-9814
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of compiler-10.0

crypto-5.1, erts-13.0, kernel-8.4, stdlib-8.0

crypto-5.9

Fixed Bugs and Malfunctions

Fixed crypto:hash_equals/2 and FIPS when crypto is statically linked to the beam (with --enable-static-nifs and --disable-dynamic-ssl-lib).
Own Id: OTP-20025
Related Id(s): PR-10817

Improvements and New Features

The rand:bytes/1 and rand:bytes_s/2 functions have been optimized by implementing a new internal callback function that crypto:rand_seed_alg/1 and crypto:alg_seed_alg_s/1 have been updated to use.
A new algorithm crypto_prng1, which also takes advantage of this new internal callback, has been added to crypto:rand_seed_alg/2 and crypto:rand_seed_alg_s/2. It is much faster then the existing crypto_aes, in particular for generating bytes.
Own Id: OTP-19882
Related Id(s): PR-10453, OTP-19827
In interactive mode, application crypto is automatically loaded when the crypto module is loaded. This will ensure that the correct value of configuration parameter fips_mode is used to initialize OpenSSL if module crypto is called/loaded before the application crypto has been loaded. In embedded mode, module crypto will fail to load if the application has not been loaded.
Own Id: OTP-20035
Related Id(s): PR-10830
OpenSSL engine support has been removed on Windows.
Own Id: OTP-20036
Related Id(s): PR-10836
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of crypto-5.9

erts-9.0, kernel-6.0, stdlib-3.9

debugger-7.0

Improvements and New Features

Native records as described in EEP-79 has been implemented.
A native record is a data structure similar to the traditional tuple-based records, except that is a true data type.
Native records are considered experimental in Erlang/OTP 29 and possibly also in Erlang/OTP 30, meaning that their behavior may change, potentially requiring updates to applications that use them.
Own Id: OTP-19785
Related Id(s): PR-10617
*** HIGHLIGHT ***
Tools such as the debugger, beam_lib, and xref no longer support BEAM files created before OTP 13B.
Own Id: OTP-19906
Related Id(s): PR-10519
Multi-valued comprehensions according to EEP 78 has been implemented.
Example:
```
> [I, -I || I <- lists:seq(1, 5)].
[1,-1,2,-2,3,-3,4,-4,5,-5]
```
Own Id: OTP-19942
Related Id(s): PR-9374
*** HIGHLIGHT ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of debugger-7.0

compiler-8.0, erts-15.0, kernel-10.0, stdlib-7.0, wx-2.0

dialyzer-6.0

Improvements and New Features

Native records as described in EEP-79 has been implemented.
A native record is a data structure similar to the traditional tuple-based records, except that is a true data type.
Native records are considered experimental in Erlang/OTP 29 and possibly also in Erlang/OTP 30, meaning that their behavior may change, potentially requiring updates to applications that use them.
Own Id: OTP-19785
Related Id(s): PR-10617
*** HIGHLIGHT ***
The guard BIF is_integer/3 has been added. It follows the design of the original EEP-16, only changing the name from is_between to is_integer. This BIF takes in 3 parameters, Term, LowerBound, and UpperBound.
It returns true if Term, LowerBound, and UpperBound are all integers, and LowerBound =< Term =< UpperBound; otherwise, it returns false.
Example:
```
1> I = 42.
2> is_integer(I, 0, 100).
true
```
Own Id: OTP-19809
Related Id(s): PR-10276
*** HIGHLIGHT ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of dialyzer-6.0

compiler-10.0, erts-12.0, kernel-8.0, stdlib-5.0, syntax_tools-2.0

diameter-2.7

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of diameter-2.7

erts-10.0, kernel-3.2, ssl-9.0, stdlib-5.0

edoc-1.5

Improvements and New Features

Changed behavior of EDoc so that when a module defines a private type and a private function spec uses it, that type no longer gets included in the EDoc chunk.
Own Id: OTP-20030
Related Id(s): PR-10770
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of edoc-1.5

erts-11.0, inets-5.10, kernel-7.0, stdlib-4.0, syntax_tools-2.0, xmerl-1.3.7

eldap-1.3

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964

Full runtime dependencies of eldap-1.3

asn1-3.0, erts-6.0, kernel-3.0, ssl-5.3.4, stdlib-3.4

erl_interface-5.7

Improvements and New Features

Improved name consistency of EPMD protocol messages in documentation and code. Renamed PORT_PLEASE2_REQ to PORT2_REQ and added prefix EPMD_.
Own Id: OTP-19734
Related Id(s): GH-10071, PR-10078
Replaced embedded OpenSSL MD5 implementation.
Own Id: OTP-20045
Related Id(s): PR-10870

Known Bugs and Problems

The ei API for decoding/encoding terms is not fully 64-bit compatible since terms that have a representation on the external term format larger than 2 GB cannot be handled.
Own Id: OTP-16607
Related Id(s): OTP-16608

erts-17.0

Fixed Bugs and Malfunctions

For a function such as the following:
```
bar(S0) ->
    S1 = setelement(8, S0, a),
    S2 = setelement(7, S1, b),
    setelement(5, S2, c).
```
the compiler would keep all of the calls to setelement/3 and emit extra unnecessary set_tuple_element instructions.
This has been corrected so that the compiler will never emit code that uses the set_tuple_element instruction. In a future release, support for the set_tuple_element will be removed from the runtime system.
Own Id: OTP-19751
Related Id(s): GH-10125, PR-10144
Improved the handling of the logging directory for the start script on Unix-like systems, so that it no longer crashes when $ROOTDIR/log is not writable.
Own Id: OTP-19874
Related Id(s): GH-10341, PR-10348
The -nocookie option for erl is now documented.
Own Id: OTP-19935
Related Id(s): PR-10549
beam_lib:strip/1 will now retain the Beam debug information chunk produced by the beam_debug_info option. The chunk will also be retained when combing the beam_debug_info option with the undocumented slim option.
The runtime system will no longer crash when attempting to load modules that have been compiled with beam_debug_info but lack the actual Beam debug info chunk.
Own Id: OTP-19991
Related Id(s): GH-10557, PR-10735
Fixed potential symbol clashing on MacOS by passing RTLD_LOCAL to dlopen. This will make symbols to not be resolvable between subsequently loaded NIF/drivers, which is the default behavior on Linux and BSD.
Own Id: OTP-20026
Related Id(s): PR-10805
The configure script used to call isfinite() with argument 0. That could fail on some platforms. This has been changed to call isfinite() with 1.0 instead.
Own Id: OTP-20088
Related Id(s): PR-10965

Improvements and New Features

The exported name space of the beam executable has been cleaned to only expose symbols of documented interfaces like NIF and driver APIs. This will avoid accidental name clashes with, for example, our statically linked variants of PCRE2 and ZSTD. NIFs and drivers that abuse undocumented internal interfaces will fail to load due to this change.
Own Id: OTP-19643
Related Id(s): PR-9864
Improved name consistency of EPMD protocol messages in documentation and code. Renamed PORT_PLEASE2_REQ to PORT2_REQ and added prefix EPMD_.
Own Id: OTP-19734
Related Id(s): GH-10071, PR-10078
The JIT now generates better code for matching or creating binaries with multiple little-endian segments.
Own Id: OTP-19747
Related Id(s): PR-10126
*** HIGHLIGHT ***
In the documentation for the compile module, a section has been added with recommendations for implementors of languages running on the BEAM. Documentation has also been added for the to_abstr, to_exp, and from_abstr options.
The documentation for erlc now lists .abstr as one of the supported options.
When compiling with the to_abstr option, the resulting .abstr file now retains any -doc attributes present in the source code.
Own Id: OTP-19784
Related Id(s): PR-10230, PR-10234
*** HIGHLIGHT ***
Native records as described in EEP-79 has been implemented.
A native record is a data structure similar to the traditional tuple-based records, except that is a true data type.
Native records are considered experimental in Erlang/OTP 29 and possibly also in Erlang/OTP 30, meaning that their behavior may change, potentially requiring updates to applications that use them.
Own Id: OTP-19785
Related Id(s): PR-10617
*** HIGHLIGHT ***
Task stealing between schedulers has been further optimized.
Own Id: OTP-19793
Related Id(s): PR-9984
The guard BIF is_integer/3 has been added. It follows the design of the original EEP-16, only changing the name from is_between to is_integer. This BIF takes in 3 parameters, Term, LowerBound, and UpperBound.
It returns true if Term, LowerBound, and UpperBound are all integers, and LowerBound =< Term =< UpperBound; otherwise, it returns false.
Example:
```
1> I = 42.
2> is_integer(I, 0, 100).
true
```
Own Id: OTP-19809
Related Id(s): PR-10276
*** HIGHLIGHT ***
Calls to trace:info(_, {M,F,A}, Item), with Item as call_time, call_memory, or all, will no longer block all scheduler threads from running.
Own Id: OTP-19811
Related Id(s): PR-10207
Full support for SCTP in socket. Not (yet) supported for FreeBSD.
Own Id: OTP-19834
In the default code path for the Erlang system, the current working directory (.) is now in the last position instead of the first.
Own Id: OTP-19842
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
Tools such as the debugger, beam_lib, and xref no longer support BEAM files created before OTP 13B.
Own Id: OTP-19906
Related Id(s): PR-10519
Optimized ETS named table lookup scalability by replacing read locks with lockless atomic operations.
Own Id: OTP-19919
Related Id(s): PR-7118
Removed the undocumented dyn_erl utility.
Own Id: OTP-19933
Related Id(s): PR-10573
Added zstd:flush/2 for flushing compressed data without closing the compression context.
Own Id: OTP-19936
Related Id(s): GH-10345, PR-10511
While the iteration order for maps is undefined, it is now guaranteed that all ways of iterating over maps provides the elements in the same order. That is, all of the following ways of iterating will produce the elements in the same order:
- maps:keys/1
- maps:values/1
- maps:to_list/1
- maps:to_list(maps:iterator(M))
- Map comprehension: [{K,V} || K := V <- M]
Own Id: OTP-19963
Related Id(s): PR-10626
*** HIGHLIGHT ***
Improved the performance of code loading.
Own Id: OTP-19966
Related Id(s): PR-10615
Changed ets:update_counter/4 and ets:update_element/4 to always reject default tuples smaller than the keypos of the table. Such keyless tuples are now rejected even if the key exists in the table and the default tuple would not be used. This is a subtle semantic change but is a nicer behavior for development and testing as it will detect faulty default tuple arguments earlier.
Own Id: OTP-19975
Related Id(s): PR-10674
*** POTENTIAL INCOMPATIBILITY ***
Improved compatibility with systems that lack certain shell utilities.
Own Id: OTP-20002
Related Id(s): PR-10647
It was previously not possible to check on the socket nif load result. A successful load was self-evident, but a failure was only visible from the fact that most socket functions failed with notsup. This has now been improved such that the (socket nif) load result is visible in the info map (from socket:info/0).
Own Id: OTP-20003
A new configure option --enable-use-embedded-3pp-alternatives/ --disable-use-embedded-3pp-alternatives has been added. When enabled configure is forced to find alternatives to the embedded third-party products (3pps) in the runtime system on the OS and when disabled configure will use of all internal embedded 3pps. Currently these options affect zstd, zlib and ryu (with STL). As of OTP 29 the default is to try to find alternatives for zstd and zlib on the OS and otherwise use the built-in versions. zstd needs to be of at least version 1.5.6 to be used and zlib needs to be of at least 1.2.5 to be used.
The OS alternative to ryu needs a C++ compiler with C++17 support. Currently the alternative to ryu may cause float to string conversions to produce slightly different (but correct) results compared to ryu.
The argument embedded_3pps has been added to erlang:system_info/1. It returns a map with information about the use of embedded 3pps in the runtime system.
Own Id: OTP-20013
Related Id(s): PR-10894, PR-10986
Added support for socket functions recvmmsg() and sendmmsg().
Own Id: OTP-20015
Related Id(s): PR-10564
*** HIGHLIGHT ***
There is a new NIF function enif_term_size().
Own Id: OTP-20016
Related Id(s): PR-10782
Call trace match specs can use [Arg1, Arg2 | '_'] syntax to match functions with at least N number of arguments.
Own Id: OTP-20017
Related Id(s): PR-10754
Replaced embedded OpenSSL MD5 implementation.
Own Id: OTP-20045
Related Id(s): PR-10870
The format of the debug information stored by the beam_debug_info option (used by the edb debugger) has been updated to more easily extendible and to contain more information about call targets. (See the linked PR for more details.)
Own Id: OTP-20048
Related Id(s): PR-9814
There are new functions erlang:exit_signal/2,3 replacing the old erlang:exit/2,3. The primary purpose is better naming to distinguish between exit exceptions and exit signals. The new exit_signal functions will also avoid a historical quirk when a process sends an exit signal to itself with reason normal.
The old erlang:exit/2,3 will work as before, but it is recommended to use the new exit:signal/2,3 functions for new or modified code. Deprecation of erlang:exit/2,3 with a compiler warning is planned for OTP 30.
Own Id: OTP-20069
Related Id(s): PR-10801
The old Tcl-based implementation of erl_errno_id() has been replaced by our own implementation now supporting more errno values on modern operating systems. It now also returns the string "errno_<ERRNO_INTEGER>" corresponding to the integer given as argument if the errno integer is unknown instead of as previously just return the string "unknown".
The result of erl_errno_id() is often converted into an atom and passed as an error from a driver or a NIF.
Own Id: OTP-20076
Related Id(s): PR-10958, PR-10969
*** POTENTIAL INCOMPATIBILITY ***
When implementing an alternate distribution implementors can now use an alternate handshake complete fun of arity 4 if needed.
Own Id: OTP-20090
Related Id(s): PR-10478
The erlang:suspend_process/1 and erlang:suspend_process/2 BIFs now also suspend BIF timers that will send messages to the process if the timer was created using the PID of the process as destination. Timers created using registered names are not affected.
Own Id: OTP-20095
Related Id(s): PR-10619, PR-11004
*** POTENTIAL INCOMPATIBILITY ***

Full runtime dependencies of erts-17.0

kernel-9.0, sasl-3.3, stdlib-4.1

et-1.8

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964

Full runtime dependencies of et-1.8

erts-9.0, kernel-5.3, runtime_tools-1.10, stdlib-3.4, wx-1.2

eunit-2.11

Improvements and New Features

Added randomDelay macro.
Own Id: OTP-19997
Related Id(s): PR-10614
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of eunit-2.11

erts-9.0, kernel-11.0, stdlib-6.0

ftp-1.2.5

Fixed Bugs and Malfunctions

The odbc application is now deprecated and is planned to be removed in Erlang/OTP 30.
The ftp and ct_ftp modules are now deprecated and are planned to be removed in Erlang/OTP 30.
Own Id: OTP-19980
Related Id(s): PR-10804
*** HIGHLIGHT ***

Full runtime dependencies of ftp-1.2.5

erts-7.0, kernel-6.0, runtime_tools-1.15.1, ssl-10.2, stdlib-3.5

inets-9.7

Improvements and New Features

A new option max_connections_open has been added to the httpc HTTP client profile configuration. It limits the maximum number of concurrent HTTP handler processes that can be open simultaneously.
When the limit is reached, new requests are queued internally and started automatically as existing handlers complete. This prevents bandwidth exhaustion in high-load scenarios where too many parallel connections cause remote servers to close sockets before transfers finish (the socket_closed_remotely error).
The option can be set via httpc:set_options([{max_connections_open, 10}], Profile).
The default value is infinity (unlimited), preserving backward compatibility. The value must be a positive integer or infinity and must be greater than or equal to max_sessions.
Own Id: OTP-19587
Related Id(s): GH-8841, PR-9712
The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***
Deprecated mod_cgi and mod_actions. Scheduled to be removed in OTP 30
Own Id: OTP-20071
Related Id(s): PR-10950

Full runtime dependencies of inets-9.7

erts-14.0, kernel-9.0, mnesia-4.12, public_key-1.13, runtime_tools-1.8.14, ssl-9.0, stdlib-5.0, stdlib-6.0

jinterface-1.16

Improvements and New Features

The jinterface build now honors SOURCE_DATE_EPOCH for deterministic build of OtpErlang.jar.
Own Id: OTP-19956
Related Id(s): PR-10556
Removed prebuilt java files from source tar file to avoid issues with different version of the java runtime.
Own Id: OTP-20073
Related Id(s): PR-10951

kernel-11.0

Fixed Bugs and Malfunctions

Fixed (inet) module selection when calling (gen_tcp) listen and connect and (gen_udp) open. Depending on the order of the options, the module option (tcp_module or udp_module) was sometimes ignored.
Own Id: OTP-19695
Related Id(s): GH-9822, PR-10013
*** POTENTIAL INCOMPATIBILITY ***
The TCP/UDP compatibility layer has been fixed so that inet_backend = socket now supports socket options reuseport and reuseport_lb for gen_tcp and gen_udp.
Own Id: OTP-19917
Related Id(s): PR-10514
Some errors in config files for the application controller would result in very cryptic crashes. Error handling has been improved to ensure that the file name and line number of the offending token are now printed.
Own Id: OTP-20054
Related Id(s): GH-10214, PR-10259

Improvements and New Features

Added an option to set the erl_boot_server listen port.
Own Id: OTP-19708
Related Id(s): PR-9894
The memory footprint of some supervisors has been reduced by purging obsoleted data when the supervisor is transitioning to and from hibernation.
Own Id: OTP-19713
Related Id(s): PR-9866
Improved name consistency of EPMD protocol messages in documentation and code. Renamed PORT_PLEASE2_REQ to PORT2_REQ and added prefix EPMD_.
Own Id: OTP-19734
Related Id(s): GH-10071, PR-10078
The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
Refactored a kernel_load_completed clause in the init module for conciseness.
Own Id: OTP-19786
Related Id(s): PR-10134
Full support for SCTP in socket. Not (yet) supported for FreeBSD.
Own Id: OTP-19834
In the default code path for the Erlang system, the current working directory (.) is now in the last position instead of the first.
Own Id: OTP-19842
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
It was previously not possible to check on the socket nif load result. A successful load was self-evident, but a failure was only visible from the fact that most socket functions failed with notsup. This has now been improved such that the (socket nif) load result is visible in the info map (from socket:info/0).
Own Id: OTP-20003
Added support for socket functions recvmmsg() and sendmmsg().
Own Id: OTP-20015
Related Id(s): PR-10564
*** HIGHLIGHT ***
Added a new module called io_ansi that allows the user to emit Virtual Terminal Sequences (a.k.a. ANSI sequences) to the terminal in order to add colors/styling to text or create fully-fledged terminal applications.
io_ansi uses the local terminfo database in order to be as cross-platform compatible as possible.
It also works across nodes so that if functions on a remote node call io_ansi:fwrite/1 it will use the destination terminal's terminfo database to determine which sequences to emit. In practice, this means that you can call functions in a remote shell session that use io_ansi and it will properly detect the terminal sequences the target terminal can handle and will print using them correctly.
Own Id: OTP-20028
Related Id(s): PR-9940
*** HIGHLIGHT ***
Polished the documentation groups, essentially removed groups that did nothing but obscure the documentation.
Own Id: OTP-20029
Related Id(s): PR-10755
Added a new behavior, data_publisher, for building eventually consistent, replicated data stores across distributed nodes. This is a generalization of the pg module.
Own Id: OTP-20055
Related Id(s): PR-10426
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***
When implementing an alternate distribution implementors can now use an alternate handshake complete fun of arity 4 if needed.
Own Id: OTP-20090
Related Id(s): PR-10478

Full runtime dependencies of kernel-11.0

crypto-5.8, erts-17.0, sasl-3.0, stdlib-8.0

megaco-4.9

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of megaco-4.9

asn1-3.0, debugger-4.0, erts-12.0, et-1.5, kernel-8.0, runtime_tools-1.8.14, stdlib-2.5

mnesia-4.26

Improvements and New Features

mnesia now has new functions select_reverse/1-6 supporting iteration over tables in reverse order.
Own Id: OTP-19611
Related Id(s): GH-8993, PR-9475
The mnesia_registry module has been removed.
Own Id: OTP-19807
Related Id(s): PR-7315
*** POTENTIAL INCOMPATIBILITY ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of mnesia-4.26

erts-9.0, kernel-5.3, stdlib-5.0

observer-2.19

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of observer-2.19

erts-15.0, et-1.5, kernel-10.0, runtime_tools-2.1, stdlib-5.0, wx-2.3

odbc-2.17

Fixed Bugs and Malfunctions

The odbc application is now deprecated and is planned to be removed in Erlang/OTP 30.
The ftp and ct_ftp modules are now deprecated and are planned to be removed in Erlang/OTP 30.
Own Id: OTP-19980
Related Id(s): PR-10804
*** HIGHLIGHT ***

Improvements and New Features

Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of odbc-2.17

erts-6.0, kernel-3.0, stdlib-2.0

os_mon-2.12

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of os_mon-2.12

erts-14.0, kernel-9.0, sasl-4.2.1, stdlib-5.0

parsetools-2.8

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of parsetools-2.8

erts-6.0, kernel-3.0, stdlib-3.4

public_key-1.21

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
Added an option for relaxed encoding of certificates to allow some values to be empty. This may be used by other applications for interoperability reasons. This option is not used by the ssl application.
Own Id: OTP-19822
Related Id(s): PR-10033
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of public_key-1.21

asn1-5.0, crypto-5.8, erts-13.0, kernel-8.0, stdlib-4.0

reltool-1.1

Improvements and New Features

Removed the undocumented dyn_erl utility.
Own Id: OTP-19933
Related Id(s): PR-10573
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of reltool-1.1

erts-15.0, kernel-9.0, sasl-4.2.1, stdlib-5.0, tools-2.6.14, wx-2.3

runtime_tools-2.4

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of runtime_tools-2.4

erts-16.0, kernel-10.0, mnesia-4.12, stdlib-6.0

sasl-4.4

Fixed Bugs and Malfunctions

UNC paths are now handled on Windows.
Own Id: OTP-19949
Related Id(s): PR-10601

Improvements and New Features

Removed the undocumented dyn_erl utility.
Own Id: OTP-19933
Related Id(s): PR-10573
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of sasl-4.4

erts-15.0, kernel-6.0, stdlib-4.0, tools-2.6.14

snmp-5.20.3

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730

Full runtime dependencies of snmp-5.20.3

asn1-5.4, crypto-4.6, erts-12.0, kernel-8.0, mnesia-4.12, runtime_tools-1.8.14, stdlib-5.0

ssh-6.0

Fixed Bugs and Malfunctions

Password-based authentication has been updated to follow current security best practices. Key-based authentication remains recommended for production systems.
Own Id: OTP-19982
Related Id(s): PR-10571
Added explicit size validation guards for pre-authentication SSH messages to improve defense-in-depth against DoS attacks. Messages now have per-field size limits based on RFC specifications:
- Transport layer messages (DISCONNECT, IGNORE, DEBUG)
- Key exchange messages (DH, ECDH, DH-GEX)
- Service request messages (SERVICE_REQUEST, SERVICE_ACCEPT, EXT_INFO)
This change enhances the existing 256KB global packet size limit with granular per-message validation. Compliant implementations are not affected.
Own Id: OTP-19995
Related Id(s): PR-10739
*** POTENTIAL INCOMPATIBILITY ***
The SFTP subsystem root option now properly rejects relative paths at daemon startup. Previously, relative paths would cause unpredictable behavior as file operations resolved relative to the Erlang VM's current working directory. The option now requires an absolute path or empty string.
Own Id: OTP-20019
Related Id(s): PR-10820
*** POTENTIAL INCOMPATIBILITY ***

Improvements and New Features

Using KEX strict extension names as specified in draft-ietf-sshm-strict-kex-00. Pre standard names are still supported.
Own Id: OTP-19709
Related Id(s): PR-10115
Added an alive option to detect and terminate dead SSH connections. Functionally equivalent to OpenSSH's ClientAlive*/ServerAlive* settings.
Own Id: OTP-19750
Related Id(s): PR-10372, PR-9125
ssh:stop_deamon now uses supervisor:stop for shutting down daemons. With this change, the scenario when ssh:stop_daemon is called for a non-existing process results in calling process exiting. Previously an error tuple was returned (which was not documented).
Own Id: OTP-19801
Related Id(s): PR-10253
*** POTENTIAL INCOMPATIBILITY ***
The default key exchange algorithm is now mlkem768x25519-sha256, a hybrid quantum-resistant algorithm combining ML-KEM-768 with X25519. This provides protection against both classical and quantum computer attacks while maintaining backward compatibility through automatic fallback to other algorithms when peers don't support it.
Own Id: OTP-19965
Related Id(s): PR-10656
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
The SSH daemon now defaults to disabled for shell and exec services, implementing the "secure by default" principle. This prevents authenticated users from executing arbitrary Erlang code unless explicitly configured.
Applications requiring shell or exec functionality must now explicitly enable:
```
  %% Enable Erlang shell
  ssh:daemon(Port, [{shell, {shell, start, []}} | Options])

  %% Enable Erlang term evaluation via exec
  ssh:daemon(Port, [{exec, erlang_eval} | Options])

  %% Restore complete old behavior
  ssh:daemon(Port, [{shell, {shell, start, []}},
                    {exec, erlang_eval}
                    | Options])
```
Own Id: OTP-19969
Related Id(s): PR-10970
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
Added SFTP resource limits section to hardening guide covering max_handles, max_path, and max_files with deployment recommendations.
Own Id: OTP-20031
Related Id(s): PR-10838
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***
The SFTP subsystem is no longer enabled by default when starting an SSH daemon. To enable it, add the subsystems option explicitly:
```
ssh:daemon(Port, [{subsystems, [ssh_sftpd:subsystem_spec([])]} | Options])
```
Own Id: OTP-20078
Related Id(s): PR-10970
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
The SSH hardening guide has been improved with a timeout overview table replacing the previous image, corrected terminology ("authenticated" instead of "authorized"), and new examples for loopback binding, public key user checking, and password lockout using ETS.
Own Id: OTP-20079
Related Id(s): PR-10970
With this change usage of zlib compression algorithm in SSH is deprecated and scheduled for removal in OTP 30.0
Own Id: OTP-20099
Related Id(s): PR-11010

Full runtime dependencies of ssh-6.0

crypto-5.7, erts-14.0, kernel-10.3, public_key-1.6.1, runtime_tools-1.15.1, stdlib-8.0

ssl-11.6

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***
Post quantum hybrid algorithm x25519mlkem768 is now the most preferred key exchange group in the default configuration.
Post-quantum hybrid algorithms secp384r1mlkem1024 and secp256r1mlkem768 are supported but have to be configured. The same goes for the plain post-quantum algorithms mlkem1024, mlkem768, and mlkem512.
The most preferred signature algorithms are now post-quantum algorithms ML-DSA and SLH-DSA if such certs are available in the configuration.
All these algorithms where available in OTP-28.4 but none of them preferred and some of them changed default status.
Own Id: OTP-20070
Related Id(s): PR-10949
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
Always use secure renegotiation for TLS-1.2 specified in RFC 5746 from 2010. Interoperability fallback option should no longer be needed.
Own Id: OTP-20080
Related Id(s): PR-10979
*** POTENTIAL INCOMPATIBILITY ***

Full runtime dependencies of ssl-11.6

crypto-5.8, erts-16.0, inets-5.10.7, kernel-10.3, public_key-1.20.3, runtime_tools-1.15.1, stdlib-7.0

stdlib-8.0

Fixed Bugs and Malfunctions

Fixed an issue in digraph_utils:roots/1 where roots could be missed in some cases.
Own Id: OTP-19932
Related Id(s): PR-10510
beam_lib:strip/1 will now retain the Beam debug information chunk produced by the beam_debug_info option. The chunk will also be retained when combing the beam_debug_info option with the undocumented slim option.
The runtime system will no longer crash when attempting to load modules that have been compiled with beam_debug_info but lack the actual Beam debug info chunk.
Own Id: OTP-19991
Related Id(s): GH-10557, PR-10735
Fixed a crash when zstd:compress/2 was asked to compress empty data.
Own Id: OTP-20001
Related Id(s): GH-10650, PR-10653

Improvements and New Features

Error return values from functions in zip now also specify which file in the archive the error belongs to.
Own Id: OTP-19663
Related Id(s): PR-9899
The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
The undocumented and unsupported function lists:zf/2 is now deprecated.
Own Id: OTP-19783
Related Id(s): PR-10161
Native records as described in EEP-79 has been implemented.
A native record is a data structure similar to the traditional tuple-based records, except that is a true data type.
Native records are considered experimental in Erlang/OTP 29 and possibly also in Erlang/OTP 30, meaning that their behavior may change, potentially requiring updates to applications that use them.
Own Id: OTP-19785
Related Id(s): PR-10617
*** HIGHLIGHT ***
The new supervior:stop/1,2 functions can be used to manage the dynamic parts of a supervisor tree in an application from outside the tree but in the same application.
Own Id: OTP-19800
Related Id(s): PR-9209
Added a new constructor array:from/2.
Own Id: OTP-19815
Related Id(s): PR-10304
There are new functions for random permutation of a list: rand:shuffle/1 and rand:shuffle_s/2. They are inspired by a suggestion and discussion on ErlangForums.
Own Id: OTP-19826
Related Id(s): PR-10281
*** HIGHLIGHT ***
The undocumented functions erl_eval:extended_parse_exprs/1 and erl_eval:extended_parse_term/1 will now be faster when called with a long list of tokens. (These functions are used by qlc and the shell.)
Own Id: OTP-19838
Related Id(s): PR-10338
The unicode module now supports the Unicode 17 standard.
Own Id: OTP-19853
Related Id(s): PR-10382
Added functions to unicode for recognizing whitespaces and identifiers.
Own Id: OTP-19858
Related Id(s): PR-10387
The rand:bytes/1 and rand:bytes_s/2 functions have been optimized by implementing a new internal callback function that crypto:rand_seed_alg/1 and crypto:alg_seed_alg_s/1 have been updated to use.
A new algorithm crypto_prng1, which also takes advantage of this new internal callback, has been added to crypto:rand_seed_alg/2 and crypto:rand_seed_alg_s/2. It is much faster then the existing crypto_aes, in particular for generating bytes.
Own Id: OTP-19882
Related Id(s): PR-10453, OTP-19827
There will now be a warning when exporting variables out of a subexpression. For example:
```
case file:open(File, AllOpts = [write,{encoding,utf8}]) of
    {ok,Fd} ->
        {Fd,AllOpts}
end
```
To avoid the warning, this can be rewritten to:
```
AllOpts = [write,{encoding,utf8}],
case file:open(File, AllOpts) of
    {ok,Fd} ->
        {Fd,AllOpts}
end
```
The warning can be suppressed by giving option nowarn_export_var_subexpr to the compiler.
Own Id: OTP-19898
Related Id(s): PR-9134
*** HIGHLIGHT ***
There are new functions in the shell for returning process information.
The pi/1 function is shortcut for erlang:process_info/1. The pi/3 function takes the three numbers from a pid, constructs a pid, and calls process_info/1.
Examples:
```
1> pi(<0.90.0>).
[{current_function,{c,pinfo,1}},
{initial_call,{erlang,apply,2}},
{status,running},
...
2> pi(0, 90, 0).
[{current_function,{c,pinfo,1}},
{initial_call,{erlang,apply,2}},
{status,running},
...
```
Own Id: OTP-19903
Related Id(s): PR-10422
Tools such as the debugger, beam_lib, and xref no longer support BEAM files created before OTP 13B.
Own Id: OTP-19906
Related Id(s): PR-10519
The mcalendar module has been updated to use the much faster than before Neri-Schneider algorithm for Gregorian calendar calculations, and been extended to handle negative years.
Own Id: OTP-19912
Related Id(s): PR-10449
graph is a new module that is a functional equivalent of the digraph and digraph_utils modules.
Own Id: OTP-19922
Related Id(s): PR-10532
*** HIGHLIGHT ***

Before Erlang/OTP 29, attempting to bind variables in a comprehension would compile successfully but fail at runtime. Example:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
* exception error: bad filter 2614250

In Erlang/OTP 29, attempting to bind a variable in a comprehension will fail by default:

1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
* 5:14: matches using '=' are not allowed in comprehension qualifiers
unless the experimental 'compr_assign' language feature is enabled.
With 'compr_assign' enabled, a match 'P = E' will behave as a
strict generator 'P <-:- [E]'."

However, this example will work as expected if the compr_assign feature is enabled when starting the runtime system:

$ erl -enable-feature compr_assign
. . .
1> fh(List) -> [H || E <- List, H = erlang:phash2(E), H rem 10 =:= 0].
ok
2> fh(lists:seq(1, 10)).
[2614250]

Here is another example how compr_assign can be used:

-module(example).
-feature(compr_assign, enable).
-export([cat/1]).

cat(Files) ->
    [Char || F <- Files,
             {ok, Bin} = file:read_file(F),
             Char <- unicode:characters_to_list(Bin)].

Own Id: OTP-19927
Related Id(s): PR-9153

*** HIGHLIGHT ***

*** POTENTIAL INCOMPATIBILITY ***

Removed the undocumented dyn_erl utility.
Own Id: OTP-19933
Related Id(s): PR-10573
The functions erl_tar:add/3 and erl_tar:add/4 now accepts the {mode,Mode} option for setting the permission of the file.
Own Id: OTP-19934
Related Id(s): PR-10524
Added zstd:flush/2 for flushing compressed data without closing the compression context.
Own Id: OTP-19936
Related Id(s): GH-10345, PR-10511
There will now be a warning when using the catch operator, which has been deprecated for a long time.
It is recommended to instead use try...catch...end but is also possible to disable the warning by using the nowarn_deprecated_catch option.
Own Id: OTP-19938
Related Id(s): PR-10421
*** HIGHLIGHT ***
Multi-valued comprehensions according to EEP 78 has been implemented.
Example:
```
> [I, -I || I <- lists:seq(1, 5)].
[1,-1,2,-2,3,-3,4,-4,5,-5]
```
Own Id: OTP-19942
Related Id(s): PR-9374
*** HIGHLIGHT ***
There will now be a warning for matches that unify constructors, such as the following:
```
m({a,B} = {Y,Z}) -> . . .
```
Such a match can be rewritten to:
```
m({a=Y,B=B}) -> . . .
```
The compiler option nowarn_match_alias_pats can be used to disable the warning.
Own Id: OTP-19943
Related Id(s): PR-10433
*** HIGHLIGHT ***
The array module have been extended with several new functions. The internal representation have been changed to allow the new functionality and optimizations. Arrays serialized with term_to_binary/1 in previous releases are not compatible.
Own Id: OTP-20004
Related Id(s): PR-10578
*** HIGHLIGHT ***
*** POTENTIAL INCOMPATIBILITY ***
m:erl_tar will use less memory when extracting large tar entries to disk. Instead of reading each tar entry into memory, erl_tar will now stream data in chunks of 64KB. The chunk size is settable using the new {chunks,ChunkSize} option.
The new {max_size,Size} option will set a limit on the total size of extracted data to protect against filling up the disk.
Checking of symlinks has been improved. Some symlinks that were safe (such as dir/link -> ../file) used to be rejected.
Own Id: OTP-20023
Related Id(s): PR-10814, PR-10818, PR-10821
*** HIGHLIGHT ***
Added a new module called io_ansi that allows the user to emit Virtual Terminal Sequences (a.k.a. ANSI sequences) to the terminal in order to add colors/styling to text or create fully-fledged terminal applications.
io_ansi uses the local terminfo database in order to be as cross-platform compatible as possible.
It also works across nodes so that if functions on a remote node call io_ansi:fwrite/1 it will use the destination terminal's terminfo database to determine which sequences to emit. In practice, this means that you can call functions in a remote shell session that use io_ansi and it will properly detect the terminal sequences the target terminal can handle and will print using them correctly.
Own Id: OTP-20028
Related Id(s): PR-9940
*** HIGHLIGHT ***
Polished the documentation groups, essentially removed groups that did nothing but obscure the documentation.
Own Id: OTP-20029
Related Id(s): PR-10755
The gb_sets:from_ordset/1 and gb_trees:from_orddict/1 functions would trust their inputs. If the input contained duplicates or was not properly sorted, the resulting gb_set or gb_tree would be invalid, and any number of interesting problems could occur.
In this release, these functions will raise an exception if their input is not valid. That could mean that incorrect programs that seemed to work could now stop working altogether.
There is also a new gb_trees:from_list/1 function for directly creating a gb_tree from a list.
Own Id: OTP-20061
Related Id(s): PR-10910
*** POTENTIAL INCOMPATIBILITY ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***
The json module now encodes and decodes quoted strings faster. Improvements of up to 55 percent has been measured when decoding JSON data with long strings.
The string:length/1, string:slice/2, and string:slice/3 functions have been optimized. For some strings, they can be up to twice as fast.
Own Id: OTP-20072
Related Id(s): PR-10938, PR-10948
*** HIGHLIGHT ***

Full runtime dependencies of stdlib-8.0

compiler-5.0, crypto-4.5, erts-16.0.3, kernel-11.0, sasl-3.0, syntax_tools-3.2.1

syntax_tools-4.1

Fixed Bugs and Malfunctions

merl:compile_and_load/1 could crash when compiling code containing comments.
merl:quote/2 would fail to handle literal UTF-8 encoded binaries.
Own Id: OTP-20077
Related Id(s): PR-10243, PR-10962

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
Multi-valued comprehensions according to EEP 78 has been implemented.
Example:
```
> [I, -I || I <- lists:seq(1, 5)].
[1,-1,2,-2,3,-3,4,-4,5,-5]
```
Own Id: OTP-19942
Related Id(s): PR-9374
*** HIGHLIGHT ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of syntax_tools-4.1

compiler-9.0, erts-16.0, kernel-10.3, stdlib-8.0

tftp-1.3

Improvements and New Features

The legacy and and or operators have been replaced with other language constructs.
Own Id: OTP-19744
Related Id(s): PR-10114, PR-10554, PR-10568, PR-10579, PR-10580, PR-10585, PR-10598, PR-10710, PR-10718, PR-10730
All use of legacy catch in the TFTP application has been rewritten.
In the process, deep return using exit/1 or throw/1 from callbacks has been changed to only work with throw/1, as customary. This was considered a misfeature.
Explicit loading of callback module or logger module has been removed, since that was against what one would expect for embedded mode.
Own Id: OTP-19996
Related Id(s): PR-10753
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of tftp-1.3

erts-6.0, kernel-6.0, stdlib-5.0

tools-4.2

Fixed Bugs and Malfunctions

Fixed "unbalanced parenthesis" issue when pressing TAB in emacs erlang shell.
Own Id: OTP-19921
Related Id(s): GH-8569, PR-10642
The minimum supported Emacs version for erlang-mode has been raised from 24.3 to 27.1. Compatibility shims for older Emacs versions have been removed.
The erlang-mode package version now tracks the Erlang/OTP release version (29.0) for consistent version numbers across package managers.
Own Id: OTP-20059
Related Id(s): PR-10892

Improvements and New Features

Tools such as the debugger, beam_lib, and xref no longer support BEAM files created before OTP 13B.
Own Id: OTP-19906
Related Id(s): PR-10519
The ignore_xref attribute has been handled as a post-analysis filter by build tools such as Rebar3. In this release, xref itself does the filtering, ensuring that all tooling that calls xref for any purpose can rely on these declarations to just work.
Own Id: OTP-20032
Related Id(s): PR-10592
*** HIGHLIGHT ***
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of tools-4.2

compiler-8.5, erts-15.0, erts-15.0, kernel-10.0, runtime_tools-2.1, stdlib-6.0

wx-2.6

Improvements and New Features

Documentation about how to validate the SBOM using sigstore has been added.
Own Id: OTP-19766
Related Id(s): GH-10151, PR-10187
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of wx-2.6

erts-12.0, kernel-8.0, stdlib-5.0

xmerl-2.2

Improvements and New Features

Only minor internal changes.
Own Id: OTP-19964
Added support for -unsafe attributes, which is used to mark functions as unsafe to use.
This is similar to but separate from deprecation, and the compiler will by default now generate warnings for calls to functions in Erlang/OTP that are known to be always unsafe.
Furthermore, xref can now be used to find calls to functions in another application that lack a -doc attribute (undocumented_function_calls), calls to functions in another application marked -doc false. (private_function_calls), as well as calls to unsafe functions (unsafe_function_calls).
Own Id: OTP-20066
Related Id(s): PR-10839
*** HIGHLIGHT ***

Full runtime dependencies of xmerl-2.2

erts-6.0, kernel-8.4, stdlib-2.5

Thanks to

Alexandre Rodrigues, Alex Mickelson, Andreas Hasselberg, Andrew Bennett, Bentheburrito, Bernhard M. Wiedemann, Bozhidar Batsov, Claes Nästén, Daniel Gorin, Daniel Kukula, dependabot[bot], Eksperimental, Eric Meadows-Jönsson, erlang-bot-app[bot], felipe stival, Fernando Areias, Holger Weiß, Ievgen Pyrogov, Ilya Averyanov, Ilya Klyuchnikov, Jan Uhlig, Jérôme de Bretagne, João Henrique Ferreira de Freitas, Johannes Christ, Jonatan Männchen, José Valim, krishnadas, Loïc Hoguin, loscher, Maria Scott, Marko Mindek, matt, Mend Renovate, Michael Daniels, Michał Muskała, Nelson Vides, Nick Vatamaniuc, Olexandr88, Paul Guyot, Paulo F. Oliveira, Paulo Tomé, Petr Sumbera, Preet, Radek Szymczyszyn, Rasmus Précenth, Richard Carlsson, Robert Ismo, Robin Morisset, Sam Weaver, Sébastien Saint-Sevin, Sergey Fedorov, siiky, Simon Cornish, spoo, Stefan Grundmann, Takeru Ohta, Vadim Yanitskiy, Vance Shipley, Wade Mealing, Wei Huang, williamthome, yagogarea, Zabrane, Zeyu Zhang, наб

erlang/otp OTP-29.0-rc3 OTP 29.0-rc3 on GitHub

HIGHLIGHTS

POTENTIAL INCOMPATIBILITIES

OTP-29.0

Improvements and New Features

asn1-5.5

Improvements and New Features

Full runtime dependencies of asn1-5.5

common_test-1.31

Fixed Bugs and Malfunctions

Improvements and New Features

Full runtime dependencies of common_test-1.31

compiler-10.0

Fixed Bugs and Malfunctions

Improvements and New Features

Full runtime dependencies of compiler-10.0

crypto-5.9

Fixed Bugs and Malfunctions

Improvements and New Features

Full runtime dependencies of crypto-5.9

debugger-7.0

Improvements and New Features

Full runtime dependencies of debugger-7.0

dialyzer-6.0

Improvements and New Features

Full runtime dependencies of dialyzer-6.0

diameter-2.7

Improvements and New Features

Full runtime dependencies of diameter-2.7

edoc-1.5

Improvements and New Features

Full runtime dependencies of edoc-1.5

eldap-1.3

Improvements and New Features

Full runtime dependencies of eldap-1.3

erl_interface-5.7

Improvements and New Features

Known Bugs and Problems

erts-17.0

Fixed Bugs and Malfunctions

Improvements and New Features

Full runtime dependencies of erts-17.0

et-1.8

Improvements and New Features

Full runtime dependencies of et-1.8

eunit-2.11

Improvements and New Features

Full runtime dependencies of eunit-2.11

ftp-1.2.5

Fixed Bugs and Malfunctions

Full runtime dependencies of ftp-1.2.5

inets-9.7

Improvements and New Features

Full runtime dependencies of inets-9.7

jinterface-1.16

Improvements and New Features

kernel-11.0

Fixed Bugs and Malfunctions

Improvements and New Features

Full runtime dependencies of kernel-11.0

megaco-4.9

Improvements and New Features

Full runtime dependencies of megaco-4.9

mnesia-4.26

Improvements and New Features

Full runtime dependencies of mnesia-4.26

observer-2.19

Improvements and New Features

Full runtime dependencies of observer-2.19

odbc-2.17

Fixed Bugs and Malfunctions

Improvements and New Features

Full runtime dependencies of odbc-2.17

os_mon-2.12

Improvements and New Features

Full runtime dependencies of os_mon-2.12

parsetools-2.8

Improvements and New Features

Full runtime dependencies of parsetools-2.8

public_key-1.21

erlang/otp OTP-29.0-rc3
OTP 29.0-rc3

on GitHub