Subject: Re: bug#14120: invalid load-history in emacsen that CANNOT_DUMP

From: Stefan Monnier <[email-masked]>
Date: Mon, 17 Feb 2020 10:09:59 -0500

>> FWIW, CANNOT_DUMP is a compilation option that is only meant to be used
>> as a temporary measure.  It suffers from various shortcomings (other
>> than the obvious startup cost).
>
>> So before we start trying to fix them, I'd like to know why you need to
>> use CANNOT_DUMP.
>
> I use CANNOT_DUMP on a daily basis on emacs 23.4 (the best emacs for
> poor machines. it renders very quick. I would like to profile It against
> latest emacs which I also use) It was compiled on on November 13 2019. I have suffered
> the same issue as Templeton.

Any chance you can try and investigate where/why/how that spurious value gets
pushed to `load-history`?

AFAICT the only place where `load-history` gets modified is in
lread.c:build_load_history.
Could you add some assertions there to try and catch the sucker?

        Stefan