Promoting the use of Mercurial; was: Re: gnome dvcs survey results

[Matt Mackall]

On Thu, 2009-01-08 at 15:29 -0500, Theodore Tso wrote:
> On Thu, Jan 08, 2009 at 01:23:06PM -0600, Matt Mackall wrote:
> > 
> > This argument always puzzles me. You can certainly write an 'extension'
> > as a shell script today in Mercurial, you'll just have to name it hg-foo
> > rather than 'hg foo'. And, just like git, it'll have to go through other
> > built-in commands to do its job. Nor will it have any help with argument
> > parsing, online help, etc. Extending our extension support so that we
> > can make arbitrary commands work as 'hg foo' is something nobody but you
> > has ever even hinted at.
> 
> I won't say it's an argument, but rather an observation.  And the
> obeservation is that there is a much greater level of access to the
> low-level internals of git via git's internal "plumbing" layer than
> there is available in Mercurial.

I don't think this is really true. The various debug commands expose
just about everything that exists. And there seems to be very little
demand for such functionality.

> > This of course begs the question: why does git still suck? If they have
> > six times the people power, you'd think that over the last 3 years they
> > would have pulled so far ahead in quality that hg and bzr wouldn't even
> > be on people's radars. But git's kluge-ness is deeply embedded in its
> > DNA and evolving away from that is apparently going to take geological
> > time. 
> 
> Well, two years ago, git and hg were roughly tied, at least in terms
> of the number of projects who use it, and from my perception of what
> DSCM various OSS developers might choose to use.  The Gnome DCVS
> survey came as a shock to me (and apparently others) since it has
> shown that in terms of mindshare, git has made some fairly impressive
> strides, at least in one particular community.

The git portion didn't surprise me much as git's always had much more
'press'. I'm a bit more surprised about the bzr part.

> As far as "why git does still suck", there's a loaded question if I
> ever saw one.  :-)

Yes. Sometimes I envy Linus' ability to make provocative statements. So
here's another one:

A few years ago the core Mercurial and Bzr developers met in London for
a weekend to compare notes and came to a tentative agreement that
merging the two projects would be a good idea. This idea was very
quickly torpedoed by Mark Shuttleworth's insistence that whatever
project resulted would have to have copyright held by Canonical. The
stated reason was allowing proprietary feature extensions as part of
their Launchpad strategy.

I wrote Mercurial to be Free with a capital 'F' as a reaction to the
object lesson of Bitkeeper. So entrusting my work to an organization
that had plans to embrace and extend it was just not going to happen.
Canonical continues to this day to raise doubts that they actually 'get'
Free Software (*cough* Launchpad *cough* upstreaming *cough*
closed-source kernel drivers *cough*) was just not going to happen.
Given the GNOME project's genesis in the dispute over the status of QT,
if I were the GNOME project, I'd be wary of adopting a tool like Bzr
without strong reassurances of its continued and full openness.

-- 
Mathematics is the supreme nostalgia of our time.