Re: [dev] requirements of build systems

From: Pedro Lucas Porcellis <porcellis_AT_eletrotupi.com>
Date: Tue, 1 Feb 2022 11:00:23 -0300

On Tue, Feb 01, 2022 at 09:29:55PM +0900, Pontus Stenetorp wrote:
> On Tue 01 Feb 2022, NRK wrote:
> > On Mon, Jan 31, 2022 at 12:10:27AM +0200, Petros Pateros wrote:
> > > However, it was pointed out to me that relying on mtime can give
> > > wrong results, for example: (a) if the clock is set backwards or
> > > in case of insufficient granularity in mtime then a file that gets
> > > modified might have the same mtime (b) an mmap(2)-ed file can get
> > > modified but its mtime might not get updated soon enough
> >
> > How likely is it for these situations to occur in practice? If these
> > are practical problems, then it makes sense to solve them. Otherwise
> > I think it's best not to waste resource solving theoretical
> > problems.
>
> Speaking for myself, I certainly have experienced issues with
> inaccurate timestamps on NFS for compute clusters where its use is
> very common. Not saying this as a supporter of NFS and the likes, just
> as evidence that it does occur in practice.

Yeah, but again, how common is that scenario on a regular, day-to-day
development? I think for most people out there, relying on mtime is just
perfectly fine.

I believe that generally, this kind of "futorology development thinking"
can lead to developing very messy and complex solutions, because "we
might hit that edgecase in the future that only 0.5% of users have
then". In the end it's like NRK said, in the end it's just a waste of
resources.

With best regards,
Pedro Lucas Porcellis
Received on Tue Feb 01 2022 - 15:00:23 CET