Link error when building tests on Linux

[dschaefer2]

On Linux, I get the following output from swift build --build-system swiftbuild --build-tests on a fresh library package from swift package init.

 0% [-----------------------------------------------------------------------------------]
warning: path("/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/datest.build/Debug-linux/datest_Module.build/Objects-normal/aarch64/datest_Module-master-emit-module.dia", fileLocation: nil) Could not read serialized diagnostics file: unable to find libclang []
warning: path("/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/datest.build/Debug-linux/datest_Module.build/Objects-normal/aarch64/datest.dia", fileLocation: nil) Co68% [========================================================---------------------------]
warning: unknown Argument unused during compilation: '-rdynamic' [-Wunused-command-line-argument] []
warning: path("/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/datest.build/Debug-linux/datestTests.build/Objects-normal/aarch64/datestTests-master-emit-module.dia", fileLocation: nil) Could not read serialized diagnostics file: unable to find libclang []
warning: path("/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/datest.build/Debug-linux/datestTests.build/Objects-normal/aarch64/datestTests.dia", fileLocation: nil)90% [==========================================================================---------]
error: unknown Linker command failed with exit code 1 (use -v to see invocation) []

[owenv]

@dschaefer2 which toolchain do you have installed? It may be one without swiftlang/swift#79108, which would explain the missing libclang

[owenv]

There might still be a different failure underlying that one

[dschaefer2]

It's the feb 19'th nightly. I'll update to the latest. SwiftPM and swift-build are off of main.

[dschaefer2]

OK fixed my toolchain line up. Ran it this time with -v and got a better answer:

    /home/dschaefer2/swift/toolchains/current/usr/bin/clang -target aarch64-unknown-linux-gnu --sysroot / -O0 -L/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/EagerLinkingTBDs/Debug-linux -L/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Products/Debug-linux -L/home/dschaefer2/swift/toolchains/swift-DEVELOPMENT-SNAPSHOT-2025-03-10-a-ubuntu24.04-aarch64/usr/lib @/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/datest.build/Debug-linux/datestTests.build/Objects-normal/aarch64/datestTests.LinkFileList -Xlinker -rpath -Xlinker @loader_path/Frameworks -Xlinker -rpath -Xlinker @loader_path/../Frameworks -rdynamic -lswiftCore -lswiftSwiftOnoneSupport -L/home/dschaefer2/swift/toolchains/current/usr/lib/swift/linux -L/usr/lib/swift @/home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Intermediates.noindex/datest.build/Debug-linux/datestTests.build/Objects-normal/aarch64/datestTests.autolink -o /home/dschaefer2/swift/datest/.build/aarch64-unknown-linux-gnu/Products/Debug-linux/datestTests.xctest
error: unknown Linker command failed with exit code 1 (use -v to see invocation) []
info: /lib/aarch64-linux-gnu/Scrt1.o:function _start:(.text+0x1c): error: undefined reference to 'main'
/lib/aarch64-linux-gnu/Scrt1.o:function _start:(.text+0x20): error: undefined reference to 'main'
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Looks like the warning about -rdynamic might be significant?

[neonichu]

What's the content of datestTests.LinkFileList?