I just discovered mruby, cloned it into f:\MinGW32\src\Languages\mruby,
built it with MSVC using rake.bat --build-all --trace -v and tested it a bit.
Seems way cool!

But I discovered that the generated bin/mruby-config.bat outputs this for --ldflags:

/NOLOGO /DEBUG /INCREMENTAL:NO /OPT:ICF /OPT:REF
/LIBPATH:F:\MinGW32\src\Languages\mruby\build\host\bin\/lib

How is link.exe (from bin\mruby-config.bat --ld) supposed to understand this host\bin\/lib part?
Where does it come from? It better be:

/LIBPATH:F:\MinGW32\src\Languages\mruby\build\host\bin\..\lib

or expanded to f:\MinGW32\src\Languages\mruby\build\host\lib.