Generated path to detect compiler information contains a semicolon instead of a colon

[CosmoCortney]

Describe the bug
When I update all installed packages, I always get an error message that the path to the compiler information supposedly does not exist. The path it attempts to open starts with C;/ (semi-colon) instead of C:/ (colon) and therefore results in an error.

Environment

• OS: Windows 11
• Compiler: MSVC 19.42.34435.0

To Reproduce
Steps to reproduce the behavior:

1. Go to the folder of your VCPKG installation
2. Open Terminal and run .\vcpkg.exe upgrade --no-dry-run

Expected behavior
VCPKG is expected to upgrade all installed packages

Failure logs
C:\vcpkg\buildtrees\detect_compiler\stdout-x64-windows.log

CMake Error at C:/vcpkg/scripts/ports.cmake:143 (message):
  Cannot find port:

    Directory does not exist: C;/vcpkg/scripts/detect_compiler

[Neumann-A]

Command shell ?

[autoantwort]

Iirc this happens if you try to use the mysys/mingw version of cmake outside of git bash

[CosmoCortney]

Command shell ?

yes, PowerShell to be specific, if your question refers to this

[shijunz]

Command shell ?

windows command or powershell or git bash shell , all of them same bug.

[shijunz]

I upgrade the CMAKE 3.13.3 and the bug is missed, you can try it.

[dg0yt]

This error is known to occur with CMake from MSYS or Cygwin environments (which are not MinGW environments). Check/clean your PATH environment variable.

[autoantwort]

@dg0yt Do you think it is a good idea to skip this cmake version in the vcpkg-tool and fallback to the version from vcpkg-tools.{xml,json}? Is there some path prefix to detect that version?

[dg0yt]

IMO it should be skipped in the tool.

There are many possible approaches:

• Run another CMake script, and check the output of path conversion.
• Run cmake -G, and check for the absence of Visual Studio Generators.
• Read the DLLs required by cmake.exe, and check for msys or cygwin ones.
• Just check if it is placed in <prefix>/usr/bin, that's the MSYS environment in MSYS2.
• Check for a msys or cygwin DLL in the same dir.