It seems like the process to install files isn't preserving mtime which reduces the effectiveness of other build systems which work based on mtime for computing what needs to be compiled. Specifically, one case, ft2build.h seems to get copied without preserving mtime:
/usr/bin/install -c -m 644 ./builds/unix/ft2unix.h \
{...}/darwin-osx-debug/include/ft2build.h
Here is the original file:
$ ls -lah ft2unix.h
-rw-r--r-- 1 samuel staff 3.8K 28 Mar 05:41 ft2unix.h
So, we see this result in the install prefix:
$ ls -lah ft2build.h
-rw-r--r-- 1 samuel staff 3.8K 5 Apr 03:48 ft2build.h
From install man page:
-p Preserve the modification time. Copy the file, as if the -C
(compare and copy) option is specified, except if the target file
doesn't already exist or is different, then preserve the modifi-
cation time of the file.
-C Copy the file. If the target file already exists and the files are the same, then don't change the modifica-
tion time of the target.
-c Copy the file. This is actually the default. The -c option is only included for backwards compatibility.
Currently, it appears that freetype is using -c which is the default. Using either -C or -p seems like it would fix the problem.
Thanks
Samuel