[libcxx-commits] [libcxxabi] [libc++][Android] Support libc++ testing on Android (PR #69274)

[Ryan Prichard via libcxx-commits]

rprichard wrote:

It looks like black/darker rejects the new Python code I added, but somehow the GitHub check passed anyway (https://github.com/llvm/llvm-project/pull/69274/checks).

After looking at llvm/utils/git/code-format-helper.py some more, I see that it is discarding stderr output from `darker` and from `git-clang-format`.

https://github.com/llvm/llvm-project/blob/7f7a15c3579c4d736e1cfaa7a4097f5a7afd9526/llvm/utils/git/code-format-helper.py#L145-L151

https://github.com/llvm/llvm-project/blob/7f7a15c3579c4d736e1cfaa7a4097f5a7afd9526/llvm/utils/git/code-format-helper.py#L94-L101

`capture_output=True` means `stdout=PIPE stderr=PIPE`, but `proc.stderr` is discarded. `""` and `None` are both false, so if the code-formatter fails to run, that's considered a quiet success. It should at least record the stderr somewhere, and probably should fail the check, so someone notices.

https://github.com/llvm/llvm-project/pull/69274