Bazel enabled repo as a git submodule/subtree

[Sailesh Mittal]

Hi all,

I have a use case where I want to put my_library, which has a WORKSPACE file at top since it is bazel enabled, to be included in another parent repo as a git subtree. I want the parent repo to be also bazel enabled. Is this setup possible?

For example, can I use relative paths in BUILD files instead of starting with "//" so that I can change the location of WORKSPACE? Or is there any clean way to do it at all?

Thanks,
Sailesh

[Sailesh Mittal]

Part of my answer is here:

http://bazel.io/docs/be/workspace.html#git_repository

Using git_repository and local_repository, I can achieve most of the things I was looking for.

Still have some questions about developing in these two different repos.

1. git_repository requires a commit or tag, which means any change in my_library must be accompanied by a commit in application repo. Can I say "latest"?

2. local_repository requires an absolute path to the repo. Can this is relative path so that I can make my_library as part of my application using git-subtree?

Thanks,

Sailesh

[Kristina Chodorow]

1. git_repository requires a commit or tag, which means any change in my_library must be accompanied by a commit in application repo. Can I say "latest"?

Bazel is designed to make builds as reproducible as possible: theoretically your build artifacts should be identical to those built on your coworker's machine if you both have the same copy of the code checked out.  Thus, allowing a tag like "latest" runs contrary to this design: depending on when you build your code, you'll get different results.

 

2. local_repository requires an absolute path to the repo. Can this is relative path so that I can make my_library as part of my application using git-subtree?

We're planning to allow this!  I've filed https://github.com/bazelbuild/bazel/issues/733 to track.

[Sailesh Mittal]

Thanks Kristina,

Created a PR for this: https://bazel-review.googlesource.com/#/c/2601/

Since this change is probably not going to be released soon, is there a way to get current directory in WORKSPACE file? Some kind of bound variable?

[Kristina Chodorow]

Actually, yes, __workspace_dir__ should be a variable you can use in the WORKSPACE file. You can probably do something like:

local_repository(

    name = "x",

    path = __workspace_dir__ + "/foo/bar"

)

I've actually got a fix in progress for #733 that covers a couple other related rules (e.g., the android_*_repo functions) and has some unit tests.  It probably won't be in until January, though.

[Sailesh Mittal]

Thanks Kristina, __workspace_dir__ works like a charm, even with relative paths using "..".

[Kristina Chodorow]

Probably it shouldn't allow .., but good (I guess).