Human readable printing of errors and conditions

[ehuelsmann]

Not all conditions and errors print 'human readable'. An example is the PROGRAM-ERROR which prints as #<PROGRAM-ERROR (some address)>, but neglects to present the exact error to the user. This applies to many more errors.

There are 2 sides to this issue:
1) Find those errors which don't
2) Resolve them

This means I hope we can collect a list here to be checked off.

[ehuelsmann]

Simple reproduction recipe:

CL-USER(1): (define-condition e2 (error) ())
-> E2

CL-USER(2): (error 'e2 :e "Just an error")

->

Debugger invoked on condition of type E2:

#<E2 {96368A}>

Restarts:

0: TOP-LEVEL Return to top level.

The same happens with (for example) PROGRAM-ERROR, which is more problematic than the example above.

[ehuelsmann]

The source of this behaviour is the fact that in some cases the 'format-control slot in the built-in condition doesn't get set.

When that happens, the print-object code in print-object.lisp doesn't get triggered to print the nice message, but rather passes control to the standard object printing routine (which prints the ugly output above).

[ehuelsmann]

Some of these have been fixed; no known others. Please reopen specific bugs for specific cases.