Tails

pinentry-gtk does not support pasting into the passphrase text entry.

From a user experience perspective, this is a regression from Tails 0.16 and older, where the Seahorse’s agent dialog did allow pasting. This was e.g. reported on our forum.

However, this is considered as a feature by upstream, on the grounds that the whole point of software such as pinentry is to ensure that secrets are not stored in insecure places like the X clipboard.

A valid workaround is to use the KeePassX Auto-Type function, we’ve documented it, so case closed.