bug#47244: 28.0.50; SIGSEGV in long-runnning Emacs

[Gregory Heytings]

> > > > > Bisection requires to know the last commit where the bug didn't 
> > > > > exist.
> > > >
> > > > Not the *last* commit, that what bisection is for to find out.  It 
> > > > just requires *any* commit where the bug didn't exist.
> > >
> > > Right, but that's unknown as well here.
> >
> > Usually the first step in bisecting is to find some distant commit 
> > where the bug did not exist.
>
> Sure, but given the time it takes to reproduce the problem, that could 
> take much longer than what Martin is doing now.  And if you go far 
> enough into the past, Emacs will stop building successfully, so you are 
> stuck there.

IIUC the problems happens once a day or so.  I'd try to see if it still 
happens with HEAD~2500, HEAD~5000, HEAD~7500, HEAD~10000.  All of them 
build successfully, and doing this doesn't cost anything.