Re: Error does not throw to debugger in 'when' block

[Michael Heerdegen]

Arthur Miller <arthur.miller@live.com> writes:

> Michael Heerdegen <michael_heerdegen@web.de> writes:
>
> Let's just do the part that matters:
>
> > For C-x C-e you need to eval a form that raises an error.  Also that
> > works as expected: evaluating the defun doesn't raise an error as
> > expected.
>
> Yes of course. As Eli said details matters.
>
> I have now looked more into it, tested another example, and I do
> understand now
> what happeneds; I just didn't know it worked that way:
>
> When called interactively with M-x, (as the command) the evaluation of the
> function exits on error, the error message is emittied, but the
> evaluation is
> not trapped in the debugger. When called from lisp, for example via: M-: it
> ends up in the debugger. I was calling it interactively, and didn't realize
> realized it worked this way. I wasn't aware that "commands" does not
> trap in the
> debugger on errors. Maybe I need to set some other of debug-on-* flags?

Only debug-on-error.  That's what I tested.  I enabled that option and
called your command in the original form and got a debugger.

[ Note there is a pitfall: M-: debug-on-error RET prints t although the
variable's value "is actually" nil - that's because M-: binds the variable
to t temporarily when evaluating the specified expression. ]


Michael.