Bazel build not respecting my git submodules

Question

I'm running a bazel build in a project that is composed of git submodules, with the following structure:

/work/
├── tensorflow/ [git submodule]
└── train/
    └── DeepSpeech/ [git submodule]
        └── native_client/

The build command looks like this:

bazel build \
    --config=monolithic \
    -c opt \
    --copt=-O3 \
    --copt="-D_GLIBCXX_USE_CXX11_ABI=0" \
    --copt=-fvisibility=hidden \
    //native_client:libdeepspeech.so \
    //native_client:generate_trie

and I'm getting the following error:

ERROR: /work/tensorflow/native_client/BUILD:6:1: Executing genrule //native_client:ds_git_version failed (Exit 1)
realpath: /work/train/DeepSpeech/native_client/../.git/: Not a directory

It seems to be complaining that /work/train/DeepSpeech/.git isn't a directory, and it would be correct because /work/train/DeepSpeech/.git is a file, containing the path to the the git tree of the git submodule.

Here are the contents of /work/train/DeepSpeech/.git:

gitdir: ../../.git/modules/train/DeepSpeech

My question is: Is there a way to have bazel respect the submodule structure of my repository? Ideally, there would be some flags I could pass in my bazel build command that would make it magically work, but I'm open to other options.

Thanks for your help!

Answer 1

Bazel indeed doesn't understand Git submodules.

Bazel however has a notion of repositories, and you can specify the structure of your repositories in the WORKSPACE file that's in the root of your workspace, using so-called repository rules.

This page explains the concept of the WORKSPACE file, and I believe this is the rule you'll need.