(not the OP-AM, just my 2c; and I wrote this just before pryrt provided better answer, but anyway)

Unlike e.g. SP 5.32, the latest SPs (e.g. 5.42) ship without the "c/bin/gdlib-config.bat" file. Perhaps an oversight by SP maintainers.

Without it, the "GD/Makefile.PL" assumes the worst on how GD was compiled, i.e. no GIF animation support. Imho, it's somewhat sloppy and convoluted anyway (see e.g. line #566) (another example: in absence of "gdlib-config", it seems to both find and _not_ to find the "c/lib/pkgconfig/gdlib.pc" file at the same time; it's quite messy).

So, to untangle everything properly seems like too heavy a task; what I did is just inject "GD_GIFANIM" into a list at line #628; and then "cpanm ." It installs smoothly and I've managed to create a simple animated GIF.