Pinentry sometimes returns the error message <character> is not bound

[equwal]

This makes it impossible to continue using StumpWM, because pinentry captures all the keybindings and declares them "not bound".

Reproduction:
Setup the pinentry and pass contribs.
(pass-copy) and select a password.
When pinentry comes up, hold DEL (ie. backspace).
The message DEL is not bound. is shown. The window is out of focus but it still captures all keysyms, making it impossible to use StumpWM.