You just need the full path to `x86_64-w64-mingw32-gcc` and nimble on the `$PATH` everything else is not required.
Example: `nim c --cpu:amd64 --os:windows --gcc.exe:/usr/bin/x86_64-w64-mingw32-gcc --gcc.linkerexe:/usr/bin/x86_64-w64-mingw32-gcc hello.nim`
