Consider the following testing arrangement (posix shell):

------

tty=$(tty)
input() {

sleep 1
printf "getpin\n"
sleep 10
printf "getpin\n"
sleep 10

}

input | pinentry-gtk-2 -T "$tty" -o 5

When the first password prompt appears, i enter a junk password like "abc" and
hit enter.

The second password prompt never appears, and pinentry-gtk-2 claims instead:

ERR 83886179 canceled

Trying the same thing on pinentry-curses or pinentry-qt4 or even pinentry-gtk-2
with $DISPLAY unset does not have this misbehavior, so i assume it's something
about the state of the GTK dialog that is causing the second GETPIN to terminate
early.

Also, if the first "sleep 10" is reduced to 4 (less than the timeout "-o 5")
then the second prompt displays as expected (but has a much shorter timeout).