How to get build times of individual targets with bazel?

Question

We have a bunch of targets being built by Bazel in our build environment today, targets being cc_binary / cc_test / cc_library etc. Is there some Bazel option that dumps build time for each of these into a file so we can analyze it after the build is done. While building Bazel dumps some timing information that disappears fast but I am looking for something (either text/XML or any other readable format) that can be used in post-build analysis.

Answer 1

To some extent this is possible. Look at the documentation: Performance profiling

There is the build flag --experimental_generate_json_trace_profile that generates a file named command.profile.gz in our outputBase dir (details about the outputBase dir can be fond here ).

Example:

bazel build --experimental_generate_json_trace_profile --experimental_profile_cpu_usage //:HelloWorld

command.profile.gz contains a file named command.profile . This can be view in Chrome ( chrome://tracing/ ).

(Tested with Bazel 2.0.0)