bug#11218: with-demoted-errors use of condition-case-unless-debug; ert

[Stefan Monnier]

>> I don't see the point of showing that info when running the tests.
>> If the user wants that info, he should be able to easily say "run this
>> test with debug-on-error" so he doesn't only get a backtrace but also
>> gets put in the debugger where he can inspect the state.

> ERT's keyboard shortcut for that is "d".  But it's not a good solution if:

> * the test is nondeterministic (maybe due to subprocess interaction),
> * the test takes a long time to run,
> * you have multiple failing tests and want to quickly compare if they are
> crashing in the same place,
> * ERT is running in batch mode (e.g. make check).

> It's better to collect as much data as reasonably possible when the error
> first occurs.

None of these arguments are really specific to ERT.  It just seems like
you like to run with debug-on-error, which is fine (I do too).
But don't impose it on all ERT users.

>> No: you'll be put in the debugger for the error "a" but if you hit `c'
>> it will continue and re-enter the debugger for error "b".
> My Emacs is a few months old, but that doesn't work for me.  Has it
> changed recently?
[...]
> If `debug-on-error' is t, `with-demoted-errors' becomes essentially
> equivalent to `progn', and (error "b") can ever be reached in

You're right, sorry: brain malfunction.
But that just means you first have to fix the bug that signals "a" before
getting to the bug that signals "b".


        Stefan