Bazel doesn't exit after build when called from CMake (ExternalProject

I am trying to build an external project that uses Bazel as its build system from CMake with Ninja. I am doing this by using ExternalProject_Add

ExternalProject_Add(bazel_proj
  SOURCE_DIR "${bazel_proj_DIR}"
  CONFIGURE_COMMAND :
  CONFIGURE_HANDLED_BY_BUILD ON
  BUILD_COMMAND bazel build //:install
  INSTALL_COMMAND bazel run //:install
  BUILD_IN_SOURCE ON
  BUILD_ALWAYS ON
  USES_TERMINAL_BUILD ON
  USES_TERMINAL_INSTALL ON
  LOG_BUILD ON
  LOG_INSTALL ON
  LOG_OUTPUT_ON_FAILURE ON
  LOG_MERGED_STDOUTERR ON
  INACTIVITY_TIMEOUT 10
)

I tried to add --worker_quit_after_build to the build command but it did not help. Bazel uses the linux-sandbox spawn strategy by default.

The only way to work around this is to stop the build with CTRL C and start over so it goes to the install step the next time!

I also could not make CMake print the progress report of Bazel to the terminal. That might be related.

CodePudding user response：

Bazel has a client/server model, where the server stays around for subsequent incremental builds. So this might be due to the server staying around. Try using the --batch startup flag, which tells bazel not to use this client/server model:

bazel --batch build //:install

https://bazel.build/docs/user-manual#batch

Note that bazel run //:install will also start the server. You could add --batch there as well, but it will probably be a bit slow because Bazel will reanalyze the build. You could possibly instead run the install program directly, which will be something like bazel-bin/install (depends on what the //:install target actually builds).