Bazel Blog

Bazel 5.2

Bazel 5.2 is a minor LTS release. It is fully backward compatible with Bazel 5.0 and 5.1 and contains selected changes by the Bazel community and Google engineers.


  • Fix running Bazel on Apple Silicon machine under QEMU. (#15223)
  • Catch NumberFormatException while trying to parse thread id. (#15434)
  • Improve the --sandbox_debug error message. (#15437)
  • Set keywords on appropriate lifecycle events. (#15440)

Apple / Xcode

  • Configure Apple crosstool to return a complete target triple that includes minimum OS version and target environment. (#15266)
  • Fix android emulator darwin_arm64 select. (#15445)


  • Remove -U_FORTIFY_SOURCE when thin_lto is enabled. (#15433)
  • Revert "Fixes incorrect install names on darwin platforms. (#15450)
  • Filter libtool warning about table of contents. (#15448)
  • SolibSymlinkAction does not need exec platform or properties. (#15474)
  • Add feature to produce serialized diagnostics files. (#15600)


  • Fix cache leak when applying transitions when only a rule's attributes change. (#15404)
  • Fix --usetopleveltargetsfor_symlinks with aliases. (#15446)
  • Config doesn't error on duplicate --define values. (#15473)


  • Collect C++ lcov coverage if runtime object not in runfiles. (#15299)
  • Collect coverage from ccbinary data deps of javatest. (#15216)
  • Collect coverage from ccbinary data deps of pytest. (#15298)
  • Make coverage --combined_report=lcov skip incompatible tests. (#15471)

External Dependencies

  • Bzlmod: throw on json parse exception. (#15429)
  • Add support for .ar archives. (and .deb files) (#15218)
  • Upgrade zlib to 1.2.12. (#15534)
  • Fix a bug that outputs of no-remote actions when used in combination with a disk-cache. (#15453)


  • Include jdk.crypto.mscapi in minimized Windows embedded JDK. (#15342)


  • Update PythonZipper action to use CommandLineItem.CapturingMapFn. (#15472)

Remote Execution

  • Unify sandbox/remote handling of empty TreeArtifact inputs. (#15449)
  • Improved zstd compression support for remote cache/execution. (#15372)
  • Upgrade Google Auth Version. (#15383)
  • Fix checking remote cache for omitted files in buildevent file. (#15405)
  • Add a flag to expose undeclared test outputs in unzipped form. (#15431)
  • Record additional profiling information for remotely executed actions. (#15443)
  • Fix downloading remote execution output files inside output dirs. (#15444)


  • Let Starlark tests inherit env variables. (#15217)


This release contains contributions from many people at Google, as well as Andreas Herrmann, Ben Lee, Benjamin Peterson, Brentley Jones, Dan Fleming, Denis Kurylenko, Fabian Meumertzheim, Keith Smiley, Ken Micklas, Mostyn Bramley-Moore, Niyas Sait, Oscar Bonilla, Son Luong Ngoc, Thi Doãn, Yannic, Yuval K, Zhongpeng Lin.