[libcxx-commits] [libcxx] [libc++] Run the Lit test suite against an installed version of the library (PR #96910)

[Louis Dionne via libcxx-commits]

ldionne wrote:

@mstorsjo The following Windows job is failing: https://github.com/llvm/llvm-project/actions/runs/9703339701/job/26781775745?pr=96910

```
ninja: error: 'libcxx/test/unwind-headers', needed by 'libcxx/test/CMakeFiles/install-unwind-test-suite-prefix', missing and no known rule to make it
ninja: Entering directory `D:/a/llvm-project/llvm-project/build/clang-cl-dll'
##[error]Process completed with exit code 1.
```

It is failing because we try installing the `install-unwind-test-suite-prefix` target which depends on `unwind-headers` and `unwind`, however that whole code block is gated on `LIBCXXABI_USE_LLVM_UNWINDER`. On Windows though, it looks like you're not building libunwind at all, so I don't understand why that code path is taken. Do you understand what's going on?

https://github.com/llvm/llvm-project/pull/96910