[libcxx-commits] [libcxxabi] [runtimes] Remove explicit -isysroot from the testing configurations on macOS (PR #66265)

[Louis Dionne via libcxx-commits]

ldionne wrote:

> This is going to break our builds because we always use the just built Clang (built using the bootstrap build) even on Darwin. I'm fine doing this change for `apple-*.cfg.in` configurations to better match Apple configuration, but for `llvm-*.cfg.in` I'd like to preserve the existing configuration and ideally also land https://reviews.llvm.org/D151056.

You make a good point that the current incarnation of the patch would break the bootstrapping build. However, I can actually run the compiler under `xcrun` instead and that will fix the issue for both the bootstrapping and the non-bootstrapping build. It's also closer to the exact thing you should do when running a built-from-scratch Clang on Apple platforms.

https://github.com/llvm/llvm-project/pull/66265