Split the extras param by comma

[jac-stripe]

When the bazel implementation calls into the wheel python script, it joins the extras arg by commas (

rules_python/python/whl.bzl

Line 27 in 3e167dc

args += ["--extras", ",".join(repository_ctx.attr.extras)]

).

When that arg is parsed, it should be split by commas. In the case of multiple args being passed with the same argument name, we should continue to use an Append parser, but with modifications to split by comma.

[bazel-io]

Can one of the admins verify this patch?

[mattmoor]

This is a pretty easy fix in whl.bzl, which I prefer to relying on a private class in argparse.

I would change the line you linked to:

   args += [
       "--extras=%s" % extra
       for extra in repository_ctx.attr.extras
   ]

This should do the right thing for argparse. Switching between this and gflags all the time trips me up... :-/

[mattmoor]

I should also have said: thanks for the PR!

[jac-stripe]

Great suggestion, updated

[mattmoor]

Test this please

(for the Bazel CI bot)

[mattmoor]

thanks again for the PR.