debug-on-error doesn't catch 'cannot write backup file'

debug-on-error doesn't catch 'cannot write backup file'

[Dan Jacobson]

I did  (set-variable (quote debug-on-error) t)
but that was not enough to start the dubugger when one hit
"Cannot write backup file; backing up in %backup%~"
True, I use backup-dir.el, but those words aren't from there.
And maybe it should give the whole path for where it is putting the
backup, I can't seem to find it.  Odd too that as root I couldn't
backup to where I please.  I had used EDITOR=emacs exim -Meb ...
-- 
http://jidanni.org/ Taiwan(04)25854780

Re: debug-on-error doesn't catch 'cannot write backup file'

[Kevin Rodgers]

Dan Jacobson wrote:

> I did  (set-variable (quote debug-on-error) t)
> but that was not enough to start the dubugger when one hit
> "Cannot write backup file; backing up in %backup%~"


That's because Emacs only prints a message instead of signalling an error,
which would abort the backup-buffer function (and thus probably the save-buffer
function).  Perhaps backup-buffer should signal an error that is ignored by
default, but which users could explicitly un-ignore.


> True, I use backup-dir.el, but those words aren't from there.


Correct.


> And maybe it should give the whole path for where it is putting the
> backup, I can't seem to find it.


I agree, the path should not be trucated via file-name-nondirectory.

> Odd too that as root I couldn't
> backup to where I please.  I had used EDITOR=emacs exim -Meb ...

Indeed.  It would take some debugging to first determine which function in

backup-buffer is signalling the error that is caught and then reported via
the "Cannot write backup file" message.


-- 
<a href="mailto:&lt;kevin.rodgers&#64;ihs.com&gt;">Kevin Rodgers</a>

Re: debug-on-error doesn't catch 'cannot write backup file'

[Richard Stallman]

    I did  (set-variable (quote debug-on-error) t)
    but that was not enough to start the dubugger when one hit
    "Cannot write backup file; backing up in %backup%~"

That is not an error.  If it were an error, it would make the command
fail, and that is not desirable.