Releasing a version#


  • Make sure that and are up to date with the latest news in the release.

  • Check that VERSION symbols in include/blosc2.h contains the correct info.

  • If API/ABI changes, please increase the minor number (e.g. 2.15 -> 2.16) and bump the SOVERSION in blosc/CMakeLists.txt. When in doubt on when SOVERSION should change, see these nice guidelines: conda-forge/c-blosc2-feedstock#62

  • Commit the changes with:

    $ git commit -a -m "Getting ready for release X.Y.Z"
    $ git push


Create a new build/ directory, change into it and issue:

$ cmake ..
$ cmake --build .
$ ctest

Forward compatibility testing#

First, go to the compat/ directory and generate a file with the current version:

$ cd ../compat
$ export LD_LIBRARY_PATH=../build/blosc
$ gcc -o filegen filegen.c -L$LD_LIBRARY_PATH -lblosc2 -I../include
$ ./filegen compress lz4 blosc-lz4-1.y.z.cdata

In order to make sure that we are not breaking forward compatibility, link and run the compat/filegen utility against different versions of the Blosc library (suggestion: 1.3.0, 1.7.0, 1.11.1, 1.14.1, 2.0.0).

You can compile the utility with different blosc shared libraries with:

$ export LD_LIBRARY_PATH=shared_blosc_library_path
$ gcc -o filegen filegen.c -L$LD_LIBRARY_PATH -lblosc -Iblosc2.h_include_path

Then, test the file created with the new version with:

$ ./filegen decompress blosc-lz4-1.y.z.cdata

Repeat this for every codec shipped with Blosc (blosclz, lz4, lz4hc, zlib and zstd).


  • Create a tag X.Y.Z from master. Use the next message:

    $ git tag -a vX.Y.Z -m "Tagging version X.Y.Z"
  • Push the tag to the github repo:

    $ git push --tags
  • Create a new release visiting Blosc/c-blosc2 and add the release notes copying them from document.

Check documentation#

Go to blogsite actions and trigger a build by going to the last run and clicking on “Re-run all jobs”.

Wait up to 10 min and go to the blosc2 docs and check that it contains the updated docs.


  • Send an announcement to the blosc and comp.compression mailing lists. Use the file as skeleton (likely as the definitive version).

  • Toot about it from the @Blosc2 account in

Post-release actions#

  • Edit VERSION symbols in blosc/blosc2.h in master to increment the version to the next minor one (i.e. X.Y.Z –> X.Y.(Z+1).dev).

  • Create new headers for adding new features in and add this place-holder instead:

    #XXX version-specific blurb XXX#

  • Commit the changes:

    $ git commit -a -m"Post X.Y.Z release actions done"
    $ git push

That’s all folks!