Clang cannot find C++ header files on 24.04

[K20shores]

Description

Following the update of ubuntu-latest updating to Ubuntu 24.04, Ubuntu workflows with clang started failing to build. It seems that Clang cannot find the header files for much of the C++ standard library.

Anything failing on 20.04 is a non issue because we weren't really targeting that. However, clang on 24.04 does not seem to find the C++ header files.

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 20.04
• Ubuntu 22.04
• Ubuntu 24.04
• macOS 12
• macOS 13
• macOS 13 Arm64
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• Windows Server 2019
• Windows Server 2022
• Windows Server 2025

Image version and build link

I put together an action which builds our software with gcc/clang in debug/release on 20.04, 22.04, 24.04, and latest so I can see where we are failing. The action.

Is it regression?

Yes

Expected behavior

Clang finds c++ header files

Actual behavior

Clang doesn't find c++ header files

Repro steps

Create a project which uses C++ on Ubuntu 24.04 and try to compile it with clang

[vidyasagarnimmagaddi]

Hi @K20shores , Thank you for bringing this issue to our attention. We are looking into this issue and will update you on this issue after investigating.

[subir0071]

Hi @K20shores - As per reproduction steps we created a minimal CPP project and executed the workflow , but the workflow passed as expected.

Let us know if missing something.

[K20shores]

@subir0071 Your action uses the GCC compiler. Please use the clang compiler. I updated my reproduction steps to represent this. Sorry for the confusion. I see this issue with the clang compiler.

[subir0071]

I updated my workflow to select clang compiler.
This workflow now uses clang compiler and is still holding good.
We would request to kindly analyze your workflow and the repository settings.
Or, kindly let us know if make any change to our test workflow.

[subir0071]

Hope your issue is resolved.

[K20shores]

@subir0071 this is not resolved. I just got back from a two week vacation and have not yet had time to look at this