In a 64 bits systems, it fails if I try to compile a configure test with:
$ gcc -m32 -o conftest -L/usr/lib/i386-linux-gnu/ conftest.c -lfreetype /usr/bin/ld: cannot find -lfreetype collect2: ld returned 1 exit status but it is successful if I do:
$ gcc -m32 -o conftest conftest.c /usr/lib/i386-linux-gnu/libfreetype.so.6 Why can't ld find 32bit libfreetype.so.6 in the first case?
There's a difference between the runtime and development system. The linker is looking for libfreetype.so and is not finding it. The program at runtime is looking for libfreetype.so.6 and finds it.
You should install the FreeType development package.
Before going to that much effort, though, you can validate this hypothesis by first checking that libfreetype.so does not exist in /usr/lib/i386-linux-gnu, and then by using root privileges to do:
cd /usr/lib/i386-linux-gnu ln -s libfreetype.so.6 libfreetype.so and then retrying the first command line.
If that works, then remove the symlink just created and then install the FreeType development package.
ln -s command I showed), at any rate. The worst that can happen is that it isn't sufficient. However, if you continue to run into problems with the FreeType library, it isn't hard to build it for yourself.