If I ssh to another of my Gentoo boxes and run, then close, dev-util/meld, the ssh connection is held open after meld closes as though there were still a window open. When I exit the shell, the ssh connection stays running until I Ctrl-C out of it. Additionally, I have noticed that when running cfg-update on one of the two remote Gentoo boxes via ssh, cfg-update cannot start meld until I have started it manually once from the command line myself. I think this only happens the first time after a reboot, but I'm not certain. These two anomalies may be related.
Thank you for your report. To me it sounds like a bug in the software provided upstream or a misconfiguration in your system [3]. Does the same source work for you on another distribution? If it works on other distributions, but not on Gentoo Linux, I suggest to discuss this problem on a related mailing list, forum or IRC channel. I have had very good experience on the Gentoo IRC [1], of course there are also forums and mailing lists. [2] I will close this bug here, because I do not see a relation to the gentoo ebuild or the way Gentoo handles this special software package. Please provide more information, if I am wrong. [1] https://www.gentoo.org/get-involved/irc-channels/ [2] https://www.gentoo.org/support/ [3] look up the upstream forums search in their bugtracker