i can not build swift compiler. Maybe the build-script found a wrong clang, but i'm not sure.
My cmd is: utils/build-script --release-debuginfo --skip-early-swift-driver --skip-early-swiftsyntax
and i get a wrong message: fatal error: 'os/signpost.h' file not found
i have no idea how to fix it, is there anyone can help me? Thanks a lot