Re: Better startup error handling

[Christian Lynbech]

>>>>> "Stefan" == Stefan Monnier <address@hidden> writes:

>> Moreover, if Emacs is clumsy at handling errors during startup (and I
>> agree that it is), that's a problem that should be addressed generally

Stefan> If someone wants to attack this, I'm all ears.

One suggestion that at least would help me a lot debugging problems
during startup would be if emacs maintained some sort of stack of files
being loaded. In other words, whenever an exception happens, there would
be a way to see that not only did evaluation halt during such-and-such
form but it happened during the load of file B that was loaded from file
A that was in turn loaded from .emacs.

In most cases, the actual error that halts the startup provides very
little info by itself and it is almost always something that happens in
one of the many libraries that I load during startup. Moreover,
frequently the library is not really at fault but I am doing something
(or fail to do something) that is (no longer) valid for my usage of the
library. 

My .emacs is big enough that I have split it into a number of files so
when I have problems, I must normally first evaluate .emacs form by form
to find the next level culprit, then repeat the form-by-form evaluation
of that to find which library to investigate. If I had some form of
loading stack, I would know immediately.

Obviously, there is tradeoff between newbie usability and guru info
provided. It would be fine by me that such debugging info was not showed
into the face of an innocent user but still was available to the
knowledgeable. If we even could save some information about both error
and the evaluation stack leading up to it, such that one was not forced
to start over with some fancy option to get usable feedback, it would be
double good. I these modern times, a lot of people do not start emacs
from the commandline and thus may even have issues knowing how to do
that.


------------------------+-----------------------------------------------------
Christian Lynbech       | christian #\@ defun #\. dk
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Hit the philistines three times over the head with the Elisp reference manual.
                                        - address@hidden (Michael A. Petonic)