> Reproducing the error is very easy for me. All I have to do is to open any
> GIF file and it immediately crashes.
>
> The version of giflib in my release of Arch Linux is: 5.0.5

Are you sure the header files you used for building Emacs against
giflib are consistent with the library?  Latest versions of giflib use
different signatures of several functions used by Emacs, creating a
binary incompatibility with previous versions, so if you are using
headers that specify old signatures, you will get crashes.

FWIW, I'm using giflib 5.0.5 (not on GNU/Linux, though) with Emacs
without any problems.