Version numbers for VCS snapshots

[Ludovic Courtès]

Ricardo Wurmus <address@hidden> skribis:

> Should we also take some time to reconsider how we name unreleased
> versions like arbitrary git commits?

Let do that!

> So far we have been picking the latest release version (or “0.0.0” if
> there hasn’t been any release) followed by “.” and either a date or a
> guix-internal revision number, then again a “.” followed by part of the
> commit hash.
>
> I’m afraid that we might accidentally introduce conflicts with future
> release versions, e.g. when the latest release only uses two digits
> (e.g. “0.1”) and we add a revision or a date (e.g. “0.1.1” or
> “0.1.20160112”) and the next release and the next official release
> switches to three digits (e.g. “0.1.1”).
>
> Would it make sense to separate our version identifier from the actual
> release version with a different character than “.”?  Or should this be
> discussed elsewhere as it hasn’t anything to do with how we specify
> versions on the command line?

Probably.  Debian, for instance, uses “2.0.11-9” where “9” denotes the
9th package revision of upstream version “2.0.11”.  We could probably
use that convention.

In a previous discussion on this topic, I suggested that we should have
such a revision number instead of just “x.y.COMMIT”.  The extra
monotonically-increasing revision number is needed to allow upgrades to
work as expected.

So, a Git snapshot’s version number could be:

  2.0.11-3.deadbeef
    ^    ^    ^
    |    |    `— upstream commit ID
    |    |
    |    `—— 3rd Guix package revision
    |    
  latest upstream version

The next snapshot would be:

  2.0.11-4.cafeefac

WDYT?

Ludo’.