When trying to create a gnupg-encrypted backup repository, it fails when app-crypt/gnupg-2.0.22 is on the system. After downgrading gnupg to version app-crypt/gnupg-2.0.20 all works fine. I report this bug to keep it as a known issue, it should be fixed upstream. Maybe it is advisible to place a post-install-warning for the user in the ebuild when a known-to-not-working gnupg version is on the system.
As discussed with Martin this must be due to some api change in gnupg and must be fixed upstream.
Created attachment 364568 [details, diff] patch for encryption wit gpg >= 2.0.22
this has been fixed upstream recently I attached the corresponding patch from the author's git repository (applies to v1.5 as well as v1.6.1)
Fixed in 1.5, Added 1.6.1-r1 revbump with fix Thanks for the patch!