There is a typo in this line in configure.ac in fontconfig 2.11.1:
AC_DEFINE_UNQUOTED([HAVE_POSIX_FADVISE], [$fc_func_posix_fadvise], [Define to 1 if you have the 'posix_fadivse' function.])
"posix_fadivse" should be changed to "posix_fadvise"
P.S: The "Version" menu on this bug reporting form only goes up to 2.9. Please add all versions that have been released since then.
Versions 2.10 & 2.11 are added to the bugzilla configuration now.
Thanks. fixed in git.