ninja: Entering directory `out/gn'
[0/1] Regenerating ninja files
ERROR at //clang/unittests/BUILD.gn:53:13: Assignment had no effect.
  sources = [ "AllClangUnitTests.cpp" ]
            ^-------------------------
You set the variable "sources" here and it was unused before it went
out of scope.
See //clang/test/BUILD.gn:177:5: which caused the file to be included.
    "//clang/unittests",
    ^------------------
FAILED: build.ninja.stamp 
../../llvm/utils/gn/bin/mac-arm64/gn --root=../.. -q --dotfile=../../llvm/utils/gn/.gn --regeneration gen .
ninja: error: rebuilding 'build.ninja': subcommand failed
Command '['ninja', '-C', 'out/gn']' returned non-zero exit status 1.