I'd like to use quilt on a development server, which doesn't have X installed. It would be great if I could use USE="-graphviz" emerge quilt to compile without the graphviz dependencies! I don't think there's any difference in the actual install, although I suppose it would be nice to not include the 'quilt graph' command if graphviz isn't found. Sorry, I'm a complete newb to ebuilds or I'd post a patch.
Created attachment 84870 [details, diff] patch to ebuild OK, that wasn't so hard. This was against 0.42, but should work against 0.44 too.
ah, it looks like I don't know how to add a new USE flag to the system so that equery gives a decent description of it. This installs correctly now, but equery describes the graphv flag as "<unknown>".
graphviz does not require X unless you have USE=tcltk set. The patch is not correct, quilt won't work fully, as you've also noted in your first comment. Anyway, there's no need for this.