Fails to install using CLANGARM64 with `release: false`

[jlaine]

Trying to run the action with msystem: CLANGARM64 and release: false bombs with the following error:

Starting MSYS2 for the first time...
  C:\Windows\system32\cmd.exe /D /S /C C:\a\_temp\setup-msys2\msys2.cmd -c "'uname' '-a'"
  The system cannot find the path specified.
  Error: The process 'C:\Windows\system32\cmd.exe' failed with exit code 1

I have set up a minimal repository which illustrates the issue:

https://github.com/jlaine/msys2-test/

[lazka]

There is no preinstalled MSYS2 on the ARM GitHub image, see actions/partner-runner-images#88

[jlaine]

OK understood thanks for the quick feedback!