This ebuild has a manual fetch requirement and the URL is wrong. It needs a final directory of "files"; the URL of .../windows/general/Math... should be .../windows/general/files/Math...
Created attachment 94048 [details] mathematica-fonts-r1 updated with new fetch location
I haven't tested this ebuild due to an apparent bug in portage... But it really was a trivial patch, and this ebuild can likely be reviewed (and see the TWO LINE FIX, WHOA MAN!) and commited. For details about the portage bug, see bug Bug #143673
fixed, thanks for the report. Also added 5.2 while I was at it, removed the restrict nofetch from it. I'm not sure what it was good for anyway or am I missing something here ?