Highlights of the release

• Add experimental capture checking #15877
• Scaladoc: New UI design #15697

Other changes and fixes

Backend

• Set ACC_FINAL access flag to final variable accessors #15707

Coverage

• Avoid instrumentation of inline and erased definitions #15504

Erasure

• Fix #15199: Exclude JavaDefined Modules from bridge generation. #15499

Extension Methods

• Merge nested polytypes in more cases in resolveOverloaded #15636

GADTs

• Fix GADT casting when typing if expressions #15646
• Use GADT constraints in maximiseType #15544
• Add the expected type to Poly's desugaring #15570
• Allow refineUsingParent to infer GADT bounds #15706
• Avoid leaking internal types in GadtConstraint.approximation #15558
• Improve GADT usage tracing for MatchType reduction #15872
• Add gadtAddBound to ExplainingTypeComparer tracing #15819
• Avoid adding NoSymbol to gadt constraints in TypeOps.instantiateToSubType #15965

IDE Support

• Recover from TypeErrors in isErroneous #15442
• Add a guard against empty ident #15542

Initialization

• Fix #15465: Use resolveThis for outerSelect resolution #15606
• Fix #15459: Display uninitialized fields in promotion error #15488
• Fix #15363: Improve error messages for leaking of this #15364
• Make sure inner classes are checked first #15527
• Handle super accessors in initialization checker #15703

Inline

• Check is inline unapply has leading implicits #15583
• Fix #15374: Make sure prefix of outer select has the correct class symbol #15592

Java Interoperability

• Don't check import selectors for Java code #15617

JS Interoperability

• Fix #15701: Implement js.dynamicImport for dynamic module loading. #15720
• Implement support for js.new.target. #15734
• Fix #14488: Scala.js: Add compiler support for scala.Enumeration. #15770

Match Types

• Avoid null types when reducing match types #15748
• Avoid references to unbound parameters in applied type patterns #15710

Nullability

• Fix checking ctx to carry correct modes #15350

Pattern Matching

• Teach provablyDisjoint to handle FromJavaObject #15769
• Don't trust case class extractors with explicit type arguments #15669
• Space: Fix how sealed abstract classes decompose #15553
• Local classes are uncheckable (type tests) #15134
• Fix ValDef span assignment in PatternMatcher #15783
• Reject all explicitly written type references with bad bounds #15577

Pickling

• Make simplify replace type parameters inside method types #15430

Quotes

• Ignore types in macro runtime dependencies #15529

REPL

• ReplDriver.run and :load take complete input #15811
• REPL goes through a phase #15663
• Avoid assertion failure for illegal trait inheritance #15631

Reporting

• Underline assignment correctly in error message #15584
• Better error message for "implicit search must be more specific" #15747
• Provide better info on compiler crashes #15890

SemanticDB

• Handle colons in file names when producing SemanticDB #15863

Standard Library

• Fix throwReturn of NonLocalReturns to allow wider usage #15495
• Update Scala 2 library dependency to 2.13.10 #16074

Tooling

• Fix scala runner exit codes #15604
• Command line parser respects outer escaped quote #15497
• Added quotes to Scala home paths in scala and scalac scripts #15824
• Retain partial type params typying information on error #15825

Transform

• Implementation restriction: No partial functions with CFT results #15744
• Fix treatment of parameter selections via this in constructors. #15737
• Fix expansion and unexpansion of mixin qualified names #15712
• Fix #15514 in Parser #15524
• Check type arguments for bad bounds #15571

Typer

• Fix swapKey #15894
• Insert GADT casts for needy match types #15851
• Add missing dealias in isContextFunctionRef #15742
• Look for synthetic applies also under type applications #15572
• Optimize isSameType for invariant applied types with the same structure #15556
• Fix cycle detection for type aliases with wildcard arguments #15508
• Handle recursions in isFullyDefined #15443
• Do level checking on instantiation #15746
• Use fullyDefinedType for mirror synthesis #15814
• Instantiate more type variables to hard unions #15632
• Simplify level fixing scheme #15936
• Don't normalize in AppliedType#superType #15453
• Try promotion while widening arguments #15467
• Check import selectors at Typer #15477
• Turn some calls to underlying into superType. #15455
• Find more looping implicits #15481
• Fix findFunctionType for OrTypes #15478
• Fix looping implicits check #15655
• Try to avoid static symbols if leaving them would make a leak #15548
• Do not fold IsConst applied to dependent parameters #15759
• Only look for synthetic applies under TypeApply with inferred arguments #15970
• Improvements for implicit searches with top-level type variables #16001
• Better types for class type parameters #15951
• Fix tuple casting #16113
• Be even more careful when combining argument and info in computeAsSeenFrom #16070
• Be still more careful when computing denotations of class parameters #16112

Contributors

Thank you to all the contributors who made this release possible 🎉

According to git shortlog -sn --no-merges 3.2.0..3.2.1 these are:

   215 Martin Odersky
    94 Filip Łukasik
    69 Fengyun Liu
    57 Filip Zybała
    31 Dale Wijnand
    16 Paweł Marks
    14 Sébastien Doeraene
    10 Guillaume Raffin
     9 rochala
     8 Chris Kipp
     8 Som Snytt
     7 Jędrzej Rochala
     7 Nicolas Stucki
     7 Yichen Xu
     6 Jamie Thompson
     6 Tom Grigg
     5 Kacper Korban
     5 noti0na1
     2 Arman Bilge
     2 Matt Bovel
     2 Ondrej Lhotak
     2 Quentin Bernet
     2 Seth Tisue
     2 Tomasz Godzik
     1 Adrien Piquerez
     1 Florian3k
     1 Gagandeep Kalra
     1 Jentsch
     1 Kieren Davies
     1 Michał Pałka
     1 Naveen
     1 Oron Port
     1 Rubin Simons
     1 Wojciech Mazur
     1 esteban marin
     1 naveen