pkg-config on macos-10.15 prefers packages from older SDK

[tstellar]

Description

I'm seeing similar error messages reported in #2274.

error: no member named 'isless' in the global namespace
using ::isless;
      ~~^
/Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:326:9: 

From what I can tell, this is caused by the fact that in my project CMake is passing both -isysroot /Applications/Xcode_12.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk and -I/Users/runner/work/llvm-project/llvm-project/build/tools/lldb/source -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include to the compiler, which causes the compiler to use some headers from the 10.15 SDK and some from the 11.1 SDK.

My assumption is that the MacOSX11.1 SDK is the default system SDK, so there should not be includes from other SDKs. The 10.15 SDK include is added, because in my project, pkg-config is searching for libedit.pc and finds it in /usr/local/Homebrew/Library/Homebrew/os/mac/pkgconfig//10.15/libedit.pc. To fix this issue, pkg-config needs to be configured so that it looks in the /usr/local/Homebrew/Library/Homebrew/os/mac/pkgconfig//11/ directory first (or whatever directory corresponds to the default SDK on the system.

I have tested this by adding the environment variable PKG_CONFIG_PATH=/usr/local/Homebrew/Library/Homebrew/os/mac/pkgconfig/ to my build, and this fixing the issue for me.

I haven't tested other macOS environments, so it's possible this is an issue with macOS 11 and 12 as well.

Platforms affected

• Azure DevOps
• GitHub Actions

Virtual environments affected

• Ubuntu 18.04
• Ubuntu 20.04
• Ubuntu 22.04
• macOS 10.15
• macOS 11
• macOS 12
• Windows Server 2019
• Windows Server 2022

Image version and build link

Version: 20220709.1

Failing Build: https://github.com/tstellar/llvm-project/runs/7294980552
Fixed Build with PKG_CONFIG_PATH=/usr/local/Homebrew/Library/Homebrew/os/mac: https://github.com/tstellar/llvm-project/runs/7315321277

Is it regression?

No

Expected behavior

pkg-config will use a search directory that is compatible with the 'default SDK'

Actual behavior

pkg-config defaults to the 10.15 SDK.

Repro steps

1. pkg-config --cflags-only-I libedit

This should print an included path that is in the default SDK directory.

[igorboskovic3]

Hi @tstellar, thank you for reporting this, we will check it.

[mikhailkoliada]

@tstellar Hello!

By default pkg-config looks up files and constructs path using the xcode command-line tools, literally for 10.15 the path would be

-I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/editline

We have never defined the PKG_CONFIG_PATH variable anyhow, so probably there is some mess regarding your settings we can not help you with.

I am going to close the issue, but feel free to reach us out if you have questions left.

[tstellar]

@mikhailkoliada The default XCode version for the macos-10.15 image is listed as 12.4 which uses 11.1 SDK. What I'm saying is that by default pkg-config should also be using 11.1 SDK install paths instead of 10.15. The XCode default and the pkg-config default should be in agreement.