Allow a custom bazel binary name (or path)

[ollehu]

This PR allows the user to configure the bazel binary name (or path). This is useful for where I work since we use a wrapper around the binary (with a different name).

[cpsauer]

Hi, Ollie! Great to meet you. Just seeing this and your issue--sorry a little backed up over here. Thanks for being the kind of person who aims to leave things better than you found them!

I'm certainly open to this in spirit, but I'm pretty sure I recall the last person who raised this finding that the Bazel idiomatic way of doing this was to use some built-in magic Bazel functionality for wrapper scripts, rather than configure by tool. Maybe it was to put the wrapper in tools/bazel? Is that something you've already tried?

Cheers--and happy coding!
Chris

[ollehu]

Thanks for getting back to me!
That would be the optimal way forward. However, it does not apply to our case since the wrapper downloads the specified Bazel-toolchain (and other dependencies) from a Nexus binary repository. We do not rely on a local installation of Bazel (so calling bazel in the repository is not even possible). It might be possible by using Bazelisk or some shell alias.

[keith]

oh i didn't check for this and filed something similar #194

in our case we don't have a bazel in the $PATH since we're intentionally limiting the PATH to something that we're sure is hermetic. so we want to reroute this to a wrapper that manages the current install

[keith]

IMO this PR is better than mine since you can set it on the rule

[ollehu]

@cpsauer what is you stance on merging this? Missing anything or should we begin to patch our local installation?

[cpsauer]

Hey Ollie--stance is positive and want to support rather than making you maintain a patch. Just got backlogged. Sorry :/

Do want to make sure there's not a better way--e.g. you guys are pretty sure you don't want this as an environment variable, right? This seems like something you'd want inherited by all refresh_compile_command rules, even ones already defined, like :refresh_all, and this seems more like a per-setup kind of thing than a per-rule or per-repo.

I'd propose just using PATH to add your wrapper script, Ollie, but @keith, it sounds like that doesn't work for you? Anything more I should know there about the hermiticity concerns there? I presume you're passing --incompatible_strict_action_env, and that it doesn't work to put it on your path just for these calls, like PATH="<wherever_bazel_is>:$PATH" bazel run @hedron_compile_commands//:refresh_all

Edit: Ollie, might the bazel idiomatic way of doing this be to use bazelisk to get bazel and then tools/bazel to get the rest?

[keith]

Yea for sure in our case it wouldn't be in the PATH. It's just a wrapper binary at the root of the repo that makes the UX better by not requiring users to have any bazel install ahead of time, or think about version issues.

[sthornington]

oh I just made a PR for the same issue: #215

we had to make it a --define though since we actually change wrapper scripts on the command line so we need to be able to override the wrapper script to use in the subshells also via the command line, and I couldn't figure out how to override it when I did it the way that it is done here.

[ollehu]

oh I just made a PR for the same issue: #215

we had to make it a --define though since we actually change wrapper scripts on the command line so we need to be able to override the wrapper script to use in the subshells also via the command line, and I couldn't figure out how to override it when I did it the way that it is done here.

@sthornington I see. Will read your PR. Are you not overriding the binary when setting up the refresh-compile-commands rule?

[ollehu]

Nevertheless, we have had this PR as patch working at my company for some time now.
@cpsauer still hesitant to merge this? In that case, we will continue on with patching master and I can drop this from one of your issues.

[sthornington]

oh I just made a PR for the same issue: #215
we had to make it a --define though since we actually change wrapper scripts on the command line so we need to be able to override the wrapper script to use in the subshells also via the command line, and I couldn't figure out how to override it when I did it the way that it is done here.

@sthornington I see. Will read your PR. Are you not overriding the binary when setting up the refresh-compile-commands rule?

Our issue is that users need to select the specific bazel wrapper on the command line depending upon exactly where they are working, so overriding it in the refresh_compile_commands (hardcoded) is not quite enough. I could not figure out how to enable overriding such a parameter on the command line of the invocation of $BAZEL run refresh_compile_commands <???bazel_command=$BAZEL???>, for example, without putting it deeper in the rule, pulling it from ctx as a var instead of as an attr. I am open to whatever, your way is cleaner but I could not make it overridable on the command line, and I tried for several hours. (that said, I am not an expert)

[sthornington]

It's possible my need could be satisfied by yours by adding another layer of indirection - a new wrapper rule whose implementation pulls the var from ctx and then plugs that in as an argument to invocation of the refresh_compile_commands ? But again, I am learning bazel as I go here...