bug#65622: closed (Inappropriate suppression of backtrace on an error)

[GNU bug Tracking System]

Your message dated Wed, 20 Sep 2023 15:55:37 +0000
with message-id <ZQsV-W0FXuXuecv5@ACM>
and subject line Re: bug#65622: Inappropriate suppression of backtrace on an 
error
has caused the debbugs.gnu.org bug report #65622,
regarding Inappropriate suppression of backtrace on an error
to be marked as done.

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-- 
65622: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=65622
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> --- Begin Message ---
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> Subject: 
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> Inappropriate suppression of backtrace on an error
>
>
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> Date: 
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> Wed, 30 Aug 2023 13:08:26 +0000
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>
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>
> Hello, Emacs.
>
> On a recent master branch Emacs:
> (i) emacs -Q
> (ii) Insert the following into *scratch*:
>
> (defmacro hash-if (condition then-form &rest else-forms)
>   "A conditional compilation macro analogous to C's #if.
> Evaluate CONDITION at macro-expansion time.  If it is non-nil,
> expand the macro to THEN-FORM.  Otherwise expand it to ELSE-FORMS
> enclosed in a `progn' form.  ELSE-FORMS may be empty."
>   (declare (indent 2)
>            (debug (form sexp &rest sexp)))
>   (if (eval condition lexical-binding)
>       then-form
>     (cons 'progn else-forms)))
>
> (defun foo (bar)
>   (hash-if (< emacs-major-version 19)
>       (car bar)
>     (cons bar bar)))
>
> (iii) Evaluate hash-if by putting point after it and doing C-x C-e.
> (iv) Attempt to instrument foo for edebug by putting point inside foo and
>   doing C-u C-M-x.  This throws the error: "Ignoring macroexpansion
>   error: (void-function edebug-after)".
> (v) Set debug-on-error to t with M-: (setq debug-on-error t).
> (vi) Repeat (iv).  This throws the same error, without a backtrace.  This
>   lack of a backtrace is a bug.
> (vii) This backtrace is almost certainly being suppressed by a frivolous
>   condition-case, whose main purpose appears to be making debugging more
>   difficult.  ;-)
> (viii) There would appear to be no justification for "ignoring" the error
>   (void-function edebug-after).  Such error should not occur, and needs
>   debugging.
>
> -- 
> Alan Mackenzie (Nuremberg, Germany).
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
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> Re: bug#65622: Inappropriate suppression of backtrace on an error
>
>
>
>
> Date: 
>
> Wed, 20 Sep 2023 15:55:37 +0000
>
>
>
>
> Hello, Michael.
>
> The bug is now fixed.
>
> On Thu, Aug 31, 2023 at 01:16:42 +0200, Michael Heerdegen wrote:
> > Alan Mackenzie <acm@muc.de> writes:
>
> > > Hello, Emacs.
> > > (v) Set debug-on-error to t with M-: (setq debug-on-error t).
> > > (vi) Repeat (iv).  This throws the same error, without a backtrace.  This
> > >   lack of a backtrace is a bug.
>
> > I think you just need (setq eval-expression-debug-on-error t).
>
> > Stumbled over the same issue ... yesterday?, or so.  Also when debugging
> > Edebug.
>
> > Maybe people would like debug-on-error -> t taking precedence over
> > eval-expression-debug-on-error -> nil?  The danger is they turn both off
> > by default and then forget about the second one.
>
> > Michael.
>
> -- 
> Alan Mackenzie (Nuremberg, Germany).
>
>
> --- End Message ---