export CPPFLAGS="-I/opt/gtk/include"
export LDFLAGS="-L/opt/gtk/lib"
export PKG_CONFIG_PATH="/opt/gtk/lib/pkgconfig"

export LD_LIBRARY_PATH="/opt/gtk/lib"
export PATH="/opt/gtk/bin:$PATH"

./configure --prefix=/opt/gtk

make  all-recursive
make[1]: Entering directory `/home/achiad/Files/fontconfig-2.2.94'
Making all in fontconfig
make[2]: Entering directory `/home/achiad/Files/fontconfig-2.2.94/fontconfig'
make[2]: Nothing to be done for `all'.
make[2]: Leaving directory `/home/achiad/Files/fontconfig-2.2.94/fontconfig'
Making all in fc-lang
make[2]: Entering directory `/home/achiad/Files/fontconfig-2.2.94/fc-lang'
if gcc -DHAVE_CONFIG_H -I. -I. -I.. -I../src -I..  -Wall -Wpointer-arith -Wstrict-prototypes    -Wmissing-prototypes -Wmissing-declarations     -Wnested-externs -fno-strict-aliasing  -I/opt/gtk/include  -g -O2 -MT fc-lang.o -MD -MP -MF ".deps/fc-lang.Tpo" \
  -c -o fc-lang.o `test -f 'fc-lang.c' || echo './'`fc-lang.c; \
then mv -f ".deps/fc-lang.Tpo" ".deps/fc-lang.Po"; \
else rm -f ".deps/fc-lang.Tpo"; exit 1; \
fi
In file included from ../fontconfig/fcfreetype.h:27,
                 from ../src/fcint.h:39,
                 from fc-lang.c:25:
/usr/include/ft2build.h:55:38: freetype/config/ftheader.h: No such file or directory
In file included from ../src/fcint.h:39,
                 from fc-lang.c:25:
../fontconfig/fcfreetype.h:28:10: #include expects "FILENAME" or <FILENAME>
In file included from ../src/fcint.h:39,
                 from fc-lang.c:25:
../fontconfig/fcfreetype.h:33: error: syntax error before "FcFreeTypeCharIndex"
../fontconfig/fcfreetype.h:33: error: syntax error before "face"
../fontconfig/fcfreetype.h:33: warning: type defaults to `int' in declaration of `FcFreeTypeCharIndex'
../fontconfig/fcfreetype.h:33: warning: function declaration isn't a prototype
../fontconfig/fcfreetype.h:33: warning: data definition has no type or storage class
../fontconfig/fcfreetype.h:36: error: syntax error before "face"
../fontconfig/fcfreetype.h:36: warning: function declaration isn't a prototype
../fontconfig/fcfreetype.h:39: error: syntax error before "face"
../fontconfig/fcfreetype.h:39: warning: function declaration isn't a prototype
../fontconfig/fcfreetype.h:42: error: syntax error before "FT_Face"
../fontconfig/fcfreetype.h:42: warning: function declaration isn't a prototype
../fontconfig/fcfreetype.h:45: warning: type defaults to `int' in declaration of `FT_Face'
../fontconfig/fcfreetype.h:45: error: syntax error before "f"
../fontconfig/fcfreetype.h:45: warning: function declaration isn't a prototype
In file included from fc-lang.c:25:
../src/fcint.h:547: error: syntax error before "encoding"
../src/fcint.h:547: warning: function declaration isn't a prototype
make[2]: *** [fc-lang.o] Error 1
make[2]: Leaving directory `/home/achiad/Files/fontconfig-2.2.94/fc-lang'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/achiad/Files/fontconfig-2.2.94'
make: *** [all] Error 2