libtool 2.2.4 patched with both patches still fail:
...........
(lt_setenv) setting 'PATH' to
':/usr/local/src/..../lt-2.2.4-mingw-mlib/lib2/.libs:/usr/local/src/..../lt-2.2.4-mingw-mlib/lib1/.libs:/tmp/test/pkg/lt-2.2.4-mingw-mlib/lib:/tmp/test/pkg/lt-2.2.4-mingw-mlib/bin:/usr/local/src/..../lt-2.2.4-mingw-mlib/lib2/.libs:/usr/local/src/..../lt-2.2.4-mingw-mlib/lib1/.libs:c:\windows\system32;c:\windows;z:\opt\mingw\bin'
(main) lt_argv_zero : Z:/..../lt-2.2.4-mingw-mlib/appl/.libs/foo.exe
(main) newargz[0] : Z:/..../lt-2.2.4-mingw-mlib/appl/.libs/foo.exe
err:module:import_dll Library libfoo2.dll (which is needed by
L"Z:\\....\\lt-2.2.4-mingw-mlib\\appl\\.libs\\foo.exe") not found
...........
The PATH contain unix instead dos path-separator.