Always rebuilds sources with autodetected clang and ninja on linux.

Brief Issue Summary

On linux scan for kits founds /bin/clang++-X instead of /usr/bin/clang++-X, which breaks ninja (see ninja-build/ninja#1330 ninja-build/ninja#1400).

It would be nice, if scan for kits would prefer /usr/bin/compiler to /bin/compiler.

Steps to reproduce:

• Get linux os, where /bin is symlink to usr/bin (fedora 35, for example).
• Install clang
• scan for kits
• select clang kit (it would point to /bin/clang*)
• try build a project
• try build project one more time, it will rebuild all sources, even none was modified.

If you change path of clang compiler from /bin/clang to /usr/bin/clang in .local/share/CMakeTools/cmake-tools-kits.json, ninja stops to rebuild all sources and rebuilds only modified, as expected.

[bobbrow]

Thank you for reporting this. So is the problem just the usage of a symlink? In other words, if we do a realpath on it before setting it in the Kit, will that solve the problem?

In other words, if we do a realpath on it before setting it in the Kit, will that solve the problem?

I think yes. This should solve it.

[teonik]

I stumbled upon the same problem. Manually changing clang's path in cmake-tools-kits.json, as Ivan-Viktorov suggested, seems to fix this issue.

[nidefawl]

I was having the same problem.

This should be fixed in vscode-cmake-tools.
ninja, cmake and clang just keep pointing fingers at each other and provide no fix.

[bobbrow]

realpath is actually not the solution here. clang++ and clang ultimately point to the same binary and if I realpath it, you can't compile C++ anymore without additional switches. I think the solution that will work better for this is to prioritize the paths we find that are first in the $PATH when we do our deduplication.

[bobbrow]

(I started working on a fix for this, BTW)

[bobbrow]

The fix for this issue is available in 1.10 "pre-release". You can help us validate it by:

1. Opening the extensions panel in VS Code
2. Selecting the CMake Tools extension
3. Clicking the "Switch to Pre-release Version" button