Header "atomic" not found when compiling the compiler on macOS 11.1 with Xcode 12.4

[LucianoPAlmeida (Luciano Almeida)]

Hi @wilsony
I don't know about this error in specific but here are some references you may found helpful

Failing Tests while Compiling Swift on Xcode 12 with MacOS Big Sur Beta

I am trying to compile Swift for a while now. The compilation goes perfectly but some test case fails which results in the process to terminate with an exit status of 65. I am using Xcode 12 ( not beta ) and macOS Big Sur Beta. I am using this command to build the Swift compiler. utils/build-script --skip-build-benchmarks \ --skip-ios --skip-watchos --skip-tvos --swift-darwin-supported-archs "x86_64" --cmake-c-launcher="$(which sccache)" --cmake-cxx-launcher="$(which sccache)" --release-…

Problems with building the Swift compiler

Hey. Since yesterday I'm trying to build the Swift compiler but I'm always getting the exact same error: FAILED: lib/sanitizer_common/CMakeFiles/RTSanitizerCommonNoTermination.osx.dir/sanitizer_platform_limits_posix.cc.o /Users/admin/swift-source/build/Ninja-ReleaseAssert/llvm-macosx-x86_64/./bin/clang++ -DHAVE_RPC_XDR_H=0 -I/Users/admin/swift-source/llvm/projects/compiler-rt/lib/sanitizer_common/.. -Wall -std=c++11 -Wno-unused-parameter -O3 -DNDEBUG -arch arm64 -arch x86_64 -arch x86_64h -isy…

Also make sure you run update-checkout :)