Created attachment 16159 [details] [review]
fontconfig-2.5.0-libtool-2.2.patch

libtool-2.2 introduces new restrictions. So now it does not allow LT_* variables as it includes marcros:

m4_pattern_forbid([^_?LT_[A-Z_]+$])

so now build fails with the error:
***** autoconf *****
***** autoconf

configure.in:48: error: possibly undefined macro: LT_AGE
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.

Patch to workaround the problem is in attachment but I think that better fix will be to rename all LT_[A-Z_]+ variables.

Another issue I experienced is this warning:

src/Makefile.am:136: `:='-style assignments are not portable

But that's merely warning...