Created attachment 371648 [details] build.log See attached build.log
I'm still trying to figure out how on earth to fix this. Basically, if go-fuse is already installed, it turns the install routine into a noop. You can simply uninstall go-fuse and it will let you install fine. Sadly, a soft blocker doesn't fix this, and a hard blocker forces you to manually fix it.
I've commited a fix, but you may need to remove go-fuse once before the fix works.
I've added a snapshot ebuild to the tree. As a workaround for this bug, it creates a filtered GOROOT tree out of symlinks, containing everything in the real GOROOT except go-fuse.