Conceptually, your build results should be a pure function of your source tree. If I understand correctly, within Google, the cross-compilers are actually check

Conceptually, your build results should be a pure function of your source tree. If I understand correctly, within Google, the cross-compilers are actually checked in to the source tree, so that the distributed jobs will use the same compiler to build your code. It seems like currently bazel only uses whatever is in /usr/bin though[0]. For Java compilations, bazel additionally has its own jar builder that sorts the filenames and zeros the timestamps within the zip file[1]. [0]: https://github.com/google/bazel/tree/master/tools/cpp https://github.com/google/bazel/tree/master/tools/cpp [1]: https://github.com/google/bazel/tree/master/src/java_tools/buildjar/java/com/google/devtools/build/buildjar https://github.com/google/bazel/tree/master/src/java_tools/b...