Windows CI failure on PR targeting `release/6.3`

Platform Windows
,
1

Hello,

I am encountering the following error on the Windows PR builds in my PR that is up versioning swift-argument-parser (targeting release/6.3). I'm not familiar with how to fix this error, especially considering the same change on main passed CI.

[2026-01-08 20:50:14] Building 'C:\Users\swift-ci\jenkins\workspace\swift-PR-windows\swift-argument-parser' to 'T:\x86_64-unknown-windows-msvc\ArgumentParser' ...
C:\Program Files\CMake\bin\cmake.exe -B T:\x86_64-unknown-windows-msvc\ArgumentParser -S C:\Users\swift-ci\jenkins\workspace\swift-PR-windows\swift-argument-parser -G Ninja -D BUILD_SHARED_LIBS=YES -D BUILD_TESTING=NO -D CMAKE_BUILD_TYPE=Release -D CMAKE_EXE_LINKER_FLAGS=/INCREMENTAL:NO /OPT:REF /OPT:ICF -D CMAKE_FIND_PACKAGE_PREFER_CONFIG=YES -D CMAKE_INSTALL_PREFIX=T:/Program Files/Swift/Toolchains/0.0.0+Asserts/usr -D CMAKE_MAKE_PROGRAM=C:/Program Files/Microsoft Visual Studio/2022/Community/Common7/IDE/CommonExtensions/Microsoft/CMake/Ninja/ninja.exe -D CMAKE_SHARED_LINKER_FLAGS=/INCREMENTAL:NO /OPT:REF /OPT:ICF -D CMAKE_STATIC_LIBRARY_PREFIX_Swift=lib -D CMAKE_Swift_COMPILER=T:/5/bin/swiftc.exe -D CMAKE_Swift_COMPILER_TARGET=x86_64-unknown-windows-msvc -D CMAKE_Swift_COMPILER_WORKS=YES -D CMAKE_Swift_FLAGS=-sdk \"T:/Program Files/Swift/Platforms/Windows.platform/Developer/SDKs/Windows.sdk\" -gnone -Xlinker /INCREMENTAL:NO -Xlinker /OPT:REF -Xlinker /OPT:ICF -D CMAKE_Swift_FLAGS_RELEASE=-O -D CMAKE_Swift_FLAGS_RELWITHDEBINFO=-O
-- The C compiler identification is Clang 21.1.6 with GNU-like command-line
-- The Swift compiler identification is Apple 6.3
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Check for working C compiler: T:/Program Files/Swift/Toolchains/0.0.0+Asserts/usr/bin/clang.exe
-- Check for working C compiler: T:/Program Files/Swift/Toolchains/0.0.0+Asserts/usr/bin/clang.exe - broken
CMake Error at C:/Program Files/CMake/share/cmake-3.29/Modules/CMakeTestCCompiler.cmake:67 (message):
  The C compiler

    "T:/Program Files/Swift/Toolchains/0.0.0+Asserts/usr/bin/clang.exe"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: 'T:/x86_64-unknown-windows-msvc/ArgumentParser/CMakeFiles/CMakeScratch/TryCompile-090iz9'
    
    Run Build Command(s): "C:/Program Files/Microsoft Visual Studio/2022/Community/Common7/IDE/CommonExtensions/Microsoft/CMake/Ninja/ninja.exe" -v cmTC_4478b
    [1/2][ 50%][0.070s] T:\PROGRA~1\Swift\TOOLCH~1\000611~1.0_A\usr\bin\clang.exe   -O0 -g -Xclang -gcodeview -D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd -MD -MT CMakeFiles/cmTC_4478b.dir/testCCompiler.c.obj -MF CMakeFiles\cmTC_4478b.dir\testCCompiler.c.obj.d -o CMakeFiles/cmTC_4478b.dir/testCCompiler.c.obj -c T:/x86_64-unknown-windows-msvc/ArgumentParser/CMakeFiles/CMakeScratch/TryCompile-090iz9/testCCompiler.c
    [2/2][100%][0.118s] C:\Windows\system32\cmd.exe /C "cd . && T:\PROGRA~1\Swift\TOOLCH~1\000611~1.0_A\usr\bin\clang.exe -nostartfiles -nostdlib -O0 -g -Xclang -gcodeview -D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd /INCREMENTAL:NO /OPT:REF /OPT:ICF   -Xlinker /subsystem:console  -fuse-ld=lld-link CMakeFiles/cmTC_4478b.dir/testCCompiler.c.obj -o cmTC_4478b.exe -Xlinker /MANIFEST:EMBED -Xlinker /implib:cmTC_4478b.lib -Xlinker /pdb:cmTC_4478b.pdb -Xlinker /version:0.0   -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 -loldnames  && cd ."
    FAILED: cmTC_4478b.exe 
    C:\Windows\system32\cmd.exe /C "cd . && T:\PROGRA~1\Swift\TOOLCH~1\000611~1.0_A\usr\bin\clang.exe -nostartfiles -nostdlib -O0 -g -Xclang -gcodeview -D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd /INCREMENTAL:NO /OPT:REF /OPT:ICF   -Xlinker /subsystem:console  -fuse-ld=lld-link CMakeFiles/cmTC_4478b.dir/testCCompiler.c.obj -o cmTC_4478b.exe -Xlinker /MANIFEST:EMBED -Xlinker /implib:cmTC_4478b.lib -Xlinker /pdb:cmTC_4478b.pdb -Xlinker /version:0.0   -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 -loldnames  && cd ."
    clang: error: no such file or directory: '/INCREMENTAL:NO'

    clang: error: no such file or directory: '/OPT:REF'

    clang: error: no such file or directory: '/OPT:ICF'

    ninja: build stopped: subcommand failed.

I re-triggered the build a few and they always produce the same error:

Is anyone able to assist? Maybe @compnerd and/or @etcwilde

2

The problem is that the new version of swift-argument-parser has C/C++ code and you didn't adjust build.ps1 accordingly. You need to build with MSVC + Swift not clang. Changing to something like:

    -UseBuiltCompielrs Swift `
    -UseMSVCCompilers C `

should fix the issue.

3

Looks like this was done in main bumped minor version number swift argument parser by johnbute · Pull Request #85489 · swiftlang/swift · GitHub.

4

Thank you. I've updated the PR.