As bohoomil’s repo hasn’t been updated since months, the freetype and fontconfig infinality packages are outdated, upstream already moved on to 2.7 and 2.12 respectively.
Fortunately, archfan published updated PKGBUILDs and patches so that infinality can be built upon the new freetype2 and fontconfig releases: https://github.com/archfan/infinality_bundle
As freetype 2.7 uses a new truetype interpreter, it’s possible that infinality is not needed anymore to get nicely looking fonts. Haven’t tested yet.
Would be great to have some feedback from infinality users. Thanks!