# manual cross-check with pinentry-kwallet with Copy/Paste of commands to STDIN (every 2nd line) works as well
$ pinentry-kwallet
OK ready to listen to your demands
OPTION no-grab
OK
OPTION ttyname=/dev/tty
OK
OPTION ttytype=xterm
OK
OPTION lc-ctype=en_US.UTF-8
OK
OPTION lc-messages=en_US.UTF-8
OK
OPTION default-ok=_OK
OK
OPTION default-cancel=_Cancel
OK
OPTION default-prompt=PIN:
OK
OPTION touch-file=/tmp/gpg-7V8por/S.gpg-agent
OK
GETINFO pid
D 10086
OK
SETDESC Sie benötigen eine Passphrase, um den geheimen Schlüssel zu entsperren.%0ABenutzer: "Hans Wurst (Bemerkung) <email address hidden>"%0A4096-bit RSA Schlüssel, ID 0A1B2C3DC, erzeugt 2013-01-01%0A
OK
SETPROMPT Passphrase
OK
GETPIN
D foobar
OK
BYE
OK
# so the problem seems to be the way gnupg and pinentry-kwallet interplay.
# manual cross-check with pinentry-kwallet with Copy/Paste of commands to STDIN (every 2nd line) works as well
$ pinentry-kwallet en_US.UTF- 8 en_US.UTF- 8 cancel= _Cancel /tmp/gpg- 7V8por/ S.gpg-agent %0ABenutzer: "Hans Wurst (Bemerkung) <email address hidden>"%0A4096-bit RSA Schlüssel, ID 0A1B2C3DC, erzeugt 2013-01-01%0A
OK ready to listen to your demands
OPTION no-grab
OK
OPTION ttyname=/dev/tty
OK
OPTION ttytype=xterm
OK
OPTION lc-ctype=
OK
OPTION lc-messages=
OK
OPTION default-ok=_OK
OK
OPTION default-
OK
OPTION default-prompt=PIN:
OK
OPTION touch-file=
OK
GETINFO pid
D 10086
OK
SETDESC Sie benötigen eine Passphrase, um den geheimen Schlüssel zu entsperren.
OK
SETPROMPT Passphrase
OK
GETPIN
D foobar
OK
BYE
OK
# so the problem seems to be the way gnupg and pinentry-kwallet interplay.