Bazel Blog

Bazel 1.2

We've just released !

Bazel 1.2 is intended to be backward-compatible with Bazel 1.0.

Please any update problems.


  • android_binary and android_library can now depend on targets providing CcInfos. See for details.
  • Experimental support for d8 dexers (both standalone and incremental) is now available for use using --nouse_workers_with_dexbuilder --define=android_incremental_dexing_tool=d8_dexbuilder. See for details.
  • Added Desugar support for FreezePeriod#<init>.


  • Fixed an aquery bug with handling malformed queries that crashes Bazel.

macOS / iOS

  • Fixed that broke caching for all builds on macOS.


  • The cc_common.{compile,link} APIs can now be used without passing the --experimental_cc_skylark_api_enabled_packages flag.
  • Incompatible flag has been added.
  • Fields on CcLinkingOutputs are now listed.


  • --target_platform_fallback now also applies to exec / host configurations


  • Added flag to switch the default value of legacy_create_init to False. With this flag enabled, your py_binary and py_test targets will no longer behave as if empty files were implicitly littered in your runfiles tree.

Documentation and UX

  • Bazel will now prevent idle sleep during test and build actions. Note that this does not affect screensavers and will not keep a laptop awake if the user forces sleep or closes the lid. This is purely to avoid idle sleeping when the user is not interacting with the device.
  • Added support for tracking suspensions (sleeps or SIGSTOP) on macOS.
  • BUILD/.bzl execution errors now cause execution to stop, even at top-level.
  • A list of log paths will now be provided in the build output.
  • Improved runfiles documentation.

Community updates

  • Ignacio Le Fluk explained how to do , using Javascript and Typescript.

  • Sergio Fernández wrote about .

  • Ahir Reddy and Li Haoyi did a presentation at Scale By The Bay 2019: .

  • Nathan Froyd is evaluating Bazel for building Firefox (, ).

  • Oasis Digital has announced new 3-day trainings .

This release contains contributions from many people at Google, as well as Alex Kirchhoff, Andrew Suffield, Asaf Flescher, Austin Schuh, Benjamin Peterson, Bor Kae Hwang, Brian Richardson, Christy Norman, Clint Harrison, Dan Halperin, Daniel Martín, Dave Lee, David Neil, David Ostrovsky, George Gensure, Greg, Jacob Parker, Jakub Bujny, John Millikin, Keith Smiley, marcohu, Marwan Tammam, Mostyn Bramley-Moore, Peter Mounce, Ruben Das, Stepan Koltsov, Thi Don, Thi, Tomasz Strejczek, Walt Panfil, Yannic Bonenberger, Zackary Lowery.