Maybe important CPP warnings on ghcautoconf.h
cpphs 1.18.6 yields the following warning:
Warning: trailing characters after #if directive in file ... /ghcautoconf.h at line 383 col 1: AC_APPLE_UNIVERSAL_BUILD
I guess it is necessary to replace #if defined
by #ifdef
in the line
#if defined AC_APPLE_UNIVERSAL_BUILD
from the mk/config.h.in file.
Note the next line
# if defined __BIG_ENDIAN__
has the same issue.