The current ebuild for cropgui doesn't work properly, it depends on some deprecated python functions. While the original upstream page seems stale there is a github page having a newer release 0.2.0: https://github.com/jepler/cropgui It's still quite old, but it seems the code is still actively maintained, maybe we should switch to a snapshot.
commit 77ac2746662fcb33b9fd9f1dbe8a2b3c4d103316 Author: Sergey Popov <pinkbyte@gentoo.org> Date: Thu Jan 28 13:29:59 2016 +0300 media-gfx/cropgui: version bump Gentoo-Bug: 569654 Package-Manager: portage-2.2.26
Thanks, guys. For anyone else that may stumble across this bug, the 0.2 release doesn't fix the current python compatibility issue ("tostring() has been removed. Please call tobytes() instead"), but the 9999 version works great.