bug#75209: 30.0.93; Emacs reader failed to read data in "/home/nlj/.cache/org-persist/gc-lock.eld"

[Pip Cet via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

"Eli Zaretskii" <eliz@gnu.org> writes:

>> Date: Wed, 01 Jan 2025 17:41:57 +0000
>> From: Pip Cet <pipcet@protonmail.com>
>> Cc: "N. Jackson" <njackson@posteo.net>, yantar92@posteo.net, 75209@debbugs.gnu.org
>>
>> I'm assuming that the resolution was that the file was read before we
>> finished writing it.  I've run into the same issue a number of times
>> (interrupting and resuming Emacs builds leads to build failures, "make
>> bootstrap" makes them go away).
>>
>> Can we consider modifying the .elc format to have a footer indicating
>> that the file is complete?
>
> The .elc file is supposed to be created only when the compilation is
> complete and successful.  If you look at byte-compile-file, you will

You're right.  Sorry for the noise.  The most likely explanation is I
missed a "Pure Lisp storage overflowed" message which "explained" it,
because I just tried and that's what happened.

There's a bug in pin_string which assumes no purespace overflow, and
corrupts bytecode after one, so it's entirely possible that an .elc file
was truncated.  Probably not worth fixing at this point.

I'll try interrupting a few more builds when no-purespace is merged.

Pip