i don’t. i install the dev package of my distro

I think you cracked the code. I was really curious what distribution this person was using that didn’t have freetype, but missing installing the -dev package makes perfect sense and I definitely remember doing that and tearing my hair out trying to figure out why I couldn’t compile some thing that needed dev headers.

OP, install libfreetype-dev or its equivalent on your system. 90% chance that fixes it.