Fedora hardens its packages by default since Fedora 23 and the home-made
CC call to build invert-svg needs position-independent code. The flag
-fPIC is apparently harmless in basic cases since it still builds when
non-hardened and the doc implies that it would just be ignored if not
supported by the target machine. As far as I could search, adding it
should not break other people's builds.
So what the heck. That's just a temporary build tool, let's add this
flag and see if others complain!
9ba2a6724c