Figure out if CC=clang requirement can be removed about rules_swift

[pcj]

Note the remote execution bazelrc in bazel_toolchains sets build:remote --extra_toolchains=@bazel_toolchains//configs/ubuntu16_04_clang/1.1/bazel_0.17.1/cpp:cc-toolchain-clang-x86_64-default, so this may be part of the puzzle (perhaps requiring the toolchain match this one)

[jiawen]

I assume no one is working on this.

Quick question however - it seems that defining CC=clang is a strict requirement. On my system, I'm using clang-12, but my build fails if I do CC=clang-12 - apparently the match needs to be exact? Can this be relaxed to have clang as a prefix?

[keith]

Yea I think we can loosen that like this #683

[jiawen]

Yea I think we can loosen that like this #683

Thanks!

[keith]

Seems like we need this for now, so I think we'll just deal with it indefinitely