The resolution to bug #183970 was to not present default values in the
Readline frontend if using Term::ReadLine::Stub.  This means that if
libterm-readline-gnu-perl is not installed, hitting enter at the
prompt will not use the default value (as would happen in most other
frontends), but will give the empty string.  This means people hit
bugs like #407761.

In fact, the default value is not even presented to the user, so often
they will not know what a sensible value to enter would be.  And
without libterm-readline-gnu-perl, the frontend doesn't really deserve
the name 'Readline'. :)

Since it is always possible for Dialog to fall back to Readline, and
since the interface is verging on unusable without the extension, I
think it is worth considering the use of 'Recommends' instead of
'Suggests'.