4.10.0 - February 25, 2026

• Regularize, cleanup, and refactor various AWS features, especially WRT regularizing AWS-related constants. See Github 3229 for more information.
• Add extra failure handling to the daos inferencing. See Github 3238 for more information.
• Regularize, cleanup, and refactor various AWS features, especially WRT regularizing AWS-related constants. See Github 3229 for more information.
• Add compatibility with HDF5 2.0.0. See Github #3247 for more information.
• Introduce consolidated metadata Github #3225 via mode=consolidated or NCZARR_CONSOLIDATED
• Fix the H5FD_class_t problems. See Github 3202 for more information.
• Begin the consolidation of global state into two files: libdispatch/dglobal.c and include/ncglobal.h. See Github 3197 for more information.
• Modify the way xarray attribute sets are handled. See Github 3218 for more information.
• Fix Issue with Numcodecs encoding problems where integer filter parameters are being encoded as strings. See Github 3201 for more information.
• Clean up minor problems with DAP2/DAP4 code. See Github #3215 for more information.
• Cleanup RELEASE_NOTES.md. See Github 3190 for more information.
• Rebuild the S3-related code and other changes necessary to build cleanly on github actions. See Github #3159 for more information.
• Fix the problems around ncdap_test/test_manyurls.c. See Github 3182 for more information.
• Fix bug in ncdump when printing FQNs (Issue 3184). See Github 3185 for more information.
• Update macOS github runners from macos-13 to macos-14, due to deprecation.
• Fix an error compiling netCDF with AWS-S3-SDK support using cmake. See Github 3155 for more information.
• Add new environmental logging variable for netCDF4 related logging subsystem, NC4LOGGING. If libnetcdf is compiled with logging enabled, logs can be enabled at runtime by setting this environmental variable to the desired log level.
• Update ncjson.[ch] and ncproplist.[ch]. Also fix references to old API. Also fix include/netcdf_ncjson.h and include/netcdf_proplist.h builds. See Github #3086 for more information.
• Refactor drc.c to move many of its purely utility functions into dutil.c. Also change the NC_mktmp signature. Change other files to match. See Github #3094 for more information.
• Provide an auxiliary function, ncaux_parse_provenance(), that allows users to parse the _NCProperties attribute into a collection of character pointers. See Github #3088 for more information.
• Fix a namespace problem in tinyxml2.cpp. Note that this is a visual studio problem hence use of _MSC_VER. Also turn off DAP4 tests against Hyrax server until DAP4 spec problems are fixed. See Github #3089 for more information.

What's Changed

• Merge v4.9.3 wellspring changes back upstream. by @WardF in #3084
• Provide an auxilliary function that allows users to parse the _NCProperties attribute. by @DennisHeimbigner in #3088
• Correct issue with .exe installer generation. by @WardF in #3096
• Correct a syntax error in previous packaging fix. by @WardF in #3097
• Fix SIGFPE with -0.0 values and quantization by @czender in #3093
• Give config.h a higher precedence. by @drwells in #3100
• Fix reported memory leak by @WardF in #3102
• Fix bug in copying compound types with variable length fields. by @DennisHeimbigner in #3111
• Step 1 in splitting PR 3068 by @DennisHeimbigner in #3086
• Create docker_regression_testing.yml by @WardF in #3116
• Add a one-off test for java. by @WardF in #3117
• Step 2 in splitting PR 3068 by @DennisHeimbigner in #3089
• Updated copyright by @WardF in #3119
• Fix various problems with S3 related code by @DennisHeimbigner in #3090
• Broken S3 implementation for netcdf files on non-AWS + Authenticated buckets by @mannreis in #3098
• Modify provenance check "_IsNetcdf4" to check for existence of "_NCProperties" by @DennisHeimbigner in #3125
• Fix pointer type on 64-bit Windows by @WardF in #3140
• Rebase of #3138 by @WardF in #3142
• Remove strlcpy from libdispatch by @weiznich in #3138
• Updates for versioned H5Dread_chunk by @brtnfld in #3143
• Change order of operations so that data is not referenced after being freed. by @WardF in #3146
• Fix Segmentation Fault when testing URLs with no path by @mannreis in #3095
• Only conditionally copy test files by @magnusuMET in #3133
• hdf5open.c: Handle null dataspace gracefully by @Dave-Allured in #3135
• CMake: correct the byterange flag by @jmckenna in #3131
• CMake: handle _INCLUDE_DIR not leveraged at compile time by @jmckenna in #3132
• CMake: Bring nczarr dependency when enabling S3 in line with autotools by @WardF in #3149
• Create PR to support refactor of drc.c code. by @DennisHeimbigner in #3094
• Patch #3090 - Fix and test S3 enabled builds by @mannreis in #3122
• Update Software list with contribution. by @WardF in #3152
• Fix integer overflow vulnerability in NC string memory allocation by @dkjsone in #3153
• Remove unneeded dependency by @WardF in #3158
• Address logging via environmental variable issues. by @WardF in #3160
• Add failover default AWS region aws_default_region "us-east-1" by @WardF in #3164
• Added NC4LOGGING to RELEASE_NOTES.md by @WardF in #3166
• Xattr header detection fix.wif by @WardF in #3167
• nc4hdf.c: Fix overwrite with zero-length attribute by @Dave-Allured in #3169
• CMake Builder Docs: document m4 dependency by @johnwparent in #3173
• Fix an issue with using AWS S3 SDK and Cmake. by @WardF in #3174
• Updated Github MacOS runners from macos-13 to macos-14 by @WardF in #3180
• Fix bug in ncdump when printing dimension FQN by @DennisHeimbigner in #3185
• Fix the problems around ncdap_test/test_manyurls.c. by @DennisHeimbigner in #3182
• General Cleanup to provide a clean base for future PRs. by @DennisHeimbigner in #3159
• Cleanup RELEASE_NOTES.md by @DennisHeimbigner in #3190
• ticket #TSP-8629412 bug fix by @dkjsone in #3191
• ncgen unsigned suffix fix by @jatkinson1000 in #3189
• run_zero_len_att_test.sh: Improve error message by @Dave-Allured in #3170
• Fix S3 internal configuration error by @gsjaardema in #3175
• Fix UBSan warnings about out-of-range assignment by @seanm in #3210
• Clean up minor issues in DAP2+DAP4 code by @DennisHeimbigner in #3215
• Added codespell config file, fixed a bunch of spelling mistakes by @seanm in #3211
• Fixed UBSan warnings about left shifts into the sign bit by @seanm in #3207
• Fix Issue with Numcodecs encoding problems by @DennisHeimbigner in #3201
• Initial basic editorconfig support by @seanm in #3212
• Fixed UBSan warnings about offsetting a NULL pointer by @seanm in #3206
• Modify the way xarray attribute sets are handled. by @DennisHeimbigner in #3218
• Part 1 - Zarr consolidated metadata by @mannreis in #3219
• Part 2 - Zarr consolidated metadata by @mannreis in #3220
• Part 3 - Zarr consolidated metadata by @mannreis in #3221
• Part 4 - Zarr consolidated metadata by @mannreis in #3222
• Part 5 - Zarr consolidated metadata by @mannreis in #3223
• Part 6 - Zarr consolidated metadata by @mannreis in #3224
• Part 7 - Zarr consolidated metadata by @mannreis in #3225
• Initial consolidation of global state by @DennisHeimbigner in #3197
• See if we can add 'dash' shell to packages installed. by @WardF in #3235
• Fix source directory macro for FetchContent support by @WardF in #3234
• Fix H5FD_class_t problems by @DennisHeimbigner in #3237
• Document Consolidated Metadata by @mannreis in #3231
• Clean up treeview in doxygen-generated documentation by @WardF in #3245
• Fix parallel hdf5 2.0.0 by @WardF in #3247
• Add extra failure handling to the daos inferencing by @DennisHeimbigner in #3238
• Fixed UBSan warning, added missing clamping for text case by @seanm in #3209
• ncs3sdk_aws.cpp: remove duplicate function by @mannreis in #3248
• Regularize, cleanup, and refactor various AWS features by @DennisHeimbigner in #3229
• Update netcdf-test-action to @v2 by @WardF in #3252
• Updated docker-based regression testing by @WardF in #3253
• Zarr: Error logging improvement by @mannreis in #3250
• fixed make distclean by @edhartnett in #3256
• fixed warning by @edhartnett in #3258
• Fixed UBSan warnings about unaligned memory access by @seanm in #3208
• Zarr csl fully by @mannreis in #3241
• Fix regression reported in #3259 by @mannreis in #3263
• allow .ncrc loading of user defined format by @edhartnett in #3264
• Quote path parameter in shell command during isdaoscontainer by @larsgeb in #3196
• AI Guidelines by @WardF in #3297

New Contributors

• @drwells made their first contribution in #3100
• @jmckenna made their first contribution in #3131
• @dkjsone made their first contribution in #3153
• @jatkinson1000 made their first contribution in #3189
• @larsgeb made their first contribution in #3196

Full Changelog: v4.9.3...v4.10.0