Re: CVS commit: src/sys

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sat, 18 Apr 2020 10:29:33 +0000
    From:        maya%NetBSD.org@localhost
    Message-ID:  <20200418102933.GA24950%homeworld.netbsd.org@localhost>

  | I feel like it's difficult to decide which is objectively better.

It all depends upon usage patterns, and objectives.

  | CVS encourages you to keep your local changes uncommitted, so they do
  | not show up in a change to RCSID at all.

Yes, that's a problem.   I'd actually prefer it if the compiler were to
add a note (of some kind, as long as it appears in the actual binary)
with the filename, mod date, and checksum, of every file it includes in
each compilation unit.   If there's also a VCS ID of some kind that can be
associated, even better.

The point was that a single identifier for the whole build simply
isn't detailed enough to be useful in many cases - it certainly wasn't
that CVS is better than something else.

  | But as a person with access to the repository, you are in a better
  | position in this case, because the DVCS will make it easy to go back to
  | the state of the tree given a hash, even after you add changes later.

I have had an off-list discussion with wiz about some of this - part of the
point is that often the person who wants to know whether a particular
version of a file was included has no reporitory access at all.   The
repository might not even still exist.   One of the questions we would
like to be able to answer is whether two different distributions were
built with the same version of some particular file - if that file is
later discovered to have been harbouring a bug.  And it would be nice to
be able to do that in isolation (no references to anything other than the
two (binary) distributions).

  | I imagine it isn't impossible to find 'closest parent which is also in
  | the remote' and embed it as well, mitigating the "outsider can't tell
  | how far you are" concern, if someone wants to pursue that.

To my mind, within reasonable cost bounds (space and effort) the more info
that is included the better.   It is always easy to simply ignore if not
needed, or redundant, but often impossible to reconstruct if missing.

kre