> On Jul 29, 2025, at 1:18 PM, Pip Cet <pipcet@protonmail.com> wrote:
> 
> "Sean Devlin" <spd@toadstyle.org <mailto:spd@toadstyle.org>> writes:
> 
>> Hi folks,
>> 
>> I left Emacs idle overnight, and I found a crash log when I returned in
>> the morning. Please see the attached file.
>> 
>> I'm using the IGC branch, and it looks like a related assertion failed.
>> 
>> I have igc-step-interval set to 0.05, but no other configuration related to GC.
>> 
>> I don’t know how to reproduce the error.
>> 
>> Thanks!
> 
> Thanks for the report. I'm afraid we don't have very much to go on: this
> assertion in trace.c in MPS failed:
> 
>    AVER(RefSetSub(ScanStateUnfixedSummary(ss), SegSummary(seg))); /* <design/check/#.common> */
> 
> I think that means a memory structure internal to MPS must have been
> corrupted; either the ScanState on the stack, or the segment
> information.
> 
> A core dump might help us figure out more, but I don't think there is
> one, right?
> 
> Pip

Right, I don’t think there is a core dump. I can look into how to record one in
the future, but I don’t know how to reproduce this issue.

Sean