After reading that, I had to :It sounds like SDL might be being built without GLX support on your system, for some reason.
-Remove my current installation of libsdl2.
-Download the .tar.gz on this page
-Compile, then install
-Re-install Löve
After that, even if my computer seems to re-install the libsdl2 package (not sure) when I'm trying to install Löve, I was able to run everything without problem.