[Dev Branch] Building issues with MinGW-w64

[hwooo]

I tried to build customized Hack (dev branch) with MinGW-w64 environment(I used Git Bash shell) but problem was same, and faced following errors:

In file included from hb-ft.cc:32:
hb-ft.h:34:10: fatal error: ft2build.h: No such file or directory
   34 | #include <ft2build.h>
      |          ^~~~~~~~~~~~

woff2sfnt.c: In function 'main':
woff2sfnt.c:189:33: error: 'O_BINARY' undeclared (first use in this function)
  189 |         setmode(fileno(stdout), O_BINARY);
      |                                 ^~~~~~~~

These errors don't stop building, but it seems that there are some compatible issues with mingw.

Attempting ttfautohint hinting...
Warning: Option `-w G' is deprecated!  Use option `-a qsq' instead
This font is not a valid font in SFNT format with TrueType outlines.
In particular, CFF outlines are not supported.
Unable to execute ttfautohint on the Hack-Regular variant subset.  Build canceled.

This error stops building and occurs while attempting hinting to subset fonts.