Steam Deck missing stdio.h

I tried to compile an application for the steam deck when I ran into missing header files. Weirdly the correct packages seemed to be installed, so why was I missing headers?

A reddit post explained that Valve had deleted some files belonging to installed packages and the resolution was to reinstall them.

So I ran the following command and surely, my compile worked afterwards.

sudo pacman -S glibc linux-api-headers