Compile swift and its stdlib Failed!

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

Based on the tag assigned to this topic I assume you're running Linux. Would you clarify what Linux distribution you're using to build and the exact version of it?

my os is Ubuntu 18.04, i have tried clang8 and clang15, both failed.
this is a screenshot of the error message

its relative path is swift/../build/Ninja-ReleaseAssert/swift-linux-x86_64/CMakeFiles/CMakeError.log

Can you make sure that you have all of the build dependencies installed per the corresponding Dockerfile, as described in the "Installing dependencies" section of the GettingStarted.md document?