bug#58224: 29.0.50; "make bootstrap" spuriously warns: "comp.el newer than byte-compiled file"

[Eli Zaretskii]

> Date: Sun, 2 Oct 2022 16:46:01 +0000
> Cc: stefankangas@gmail.com, 58224@debbugs.gnu.org, acm@muc.de
> From: Alan Mackenzie <acm@muc.de>
> 
> > > In lread.c I've got:
> 
> > >   struct timespec epoch_timespec = {(time_t)0, 0}; /* 1970-01-01T00:00 
> > > UTC */ 
> 
> > > , which clearly isn't satisfactory.
> 
> > I'm not sure I follow: why not satisfactory?
> 
> Don't we build for operating systems with different epochs?

No, the Epoch is the same for everyone.  It's a Posix notion, AFAIK.

> > Is mktime the function you are after?
> 
> Yes thanks!  But it's horribly complicated, involving wierd readings and
> settings of the TZ environment variable, and so on.

Not if you are interested in UTC.

> If a binary zero time would do (as above), maybe it would be
> satisfactory.  ;-)

Yes.