bug#71178: Batch ert wrongly aborts a test run, and wrongly fails to say why.

[J.P.]

Hi Alan,

Alan Mackenzie <acm@muc.de> writes:

> Hello, Stefan and Emacs.
>
> In my development branch, based on master, last updated ~March 2024.
>
> (i) Build emacs.
> (ii) make -j17 check.
>
> The ert session this starts goes well, apart from in
> lisp/erc/erc-tests.el.  This gets aborted by ert after 62 from 92 tests
> have passed.  Test 63 fails for known reasons, a mismatch of two strings
> compared with `equal'.
>
> The log file, erc-tests.log, looks like this around the output for test
> 63:
>
> .........................................................
>    passed  60/92  erc--update-user-modes (0.000093 sec)
>    passed  61/92  erc--user-modes (0.000053 sec)
>    passed  62/92  erc--valid-local-channel-p (0.000071 sec)
> Test erc--with-dependent-type-match backtrace:
>
> Aborted: Ran 92 tests, 62 results as expected, 1 unexpected (2024-05-24
> 15:26:55+0000, 2.791555 sec)
>
> 1 unexpected results:
>    FAILED  erc--with-dependent-type-match
>   UNKNOWN  erc--with-entrypoint-environment
>   UNKNOWN  erc-channel-p
>   UNKNOWN  erc-channel-user

I'm afraid I must claim this as my own handiwork. My apologies.

> ........................................................
>
> Note that
> (i) No error message or backtrace gets printed for test 63.  This is a
>   bug.
> (ii) The test run gets aborted.  This shouldn't happen, and is a bug.

Yes, this is unfortunate.

> erc-tests.el runs satisfactorally in an Emacs session, started by M-x
> ert, and accepting the default selection t.

It seems you have identified the underlying cause:

  https://lists.gnu.org/archive/html/emacs-devel/2024-05/msg01140.html

The test itself is of minimal utility and is therefore rubbish (if not
outright vandalism), so I will remove it unless you'd rather it stick
around until the conversation on the list gets going.

Thanks,
J.P.