I was wondering why you were doing a full bootstrap anyway, as the CMake config forces a hosttools build on linux if building the new swift-syntax parser is enabled, but maybe your passing --skip-early-swiftsyntax disabled that. The build instructions for linux will need to be updated, I will submit a doc pull for that.
Try running utils/build-script --release-debuginfo --reconfigure and check for the following lines when CMake is run for the compiler build:
- CMake found your Swift compiler (your prebuilt compiler version will be different)
-- Swift Compiler (/opt/swift/5.8.1/usr/bin/swiftc) Version: 5.8.1
- the bootstrap is set to hosttools
-- Bootstrapping: HOSTTOOLS
- you are using the new swift-syntax parser
-- Swift parser: TRUE
I copy-pasted those three lines from the log for a recent linux CI build, your build should pass just like that one if those are properly set. If reconfiguring doesn't work, try deleting the existing Swift compiler build directory with rm -rf build/Ninja-RelWithDebInfoAssert/swift-linux-x86_64/, then running build-script again without the skip-early flags from the doc.