Repository format

[Karl Fogel]

Viktor Nagy <viktor.nagy at gmail.com> writes:
> The last time, as far as I remember, the closing state was that bzr should use
> 1.6 as it's stable and well tested, even though 1.9 is considered to be stable
> as well and is superior to 1.6. To me this argument sounds rather strange, as
> it's not cristal-clear how could then any format mature enough, and what
> actually stable means if it is not the default, but the best format.
>
> But, thankfully, given the friendly and detailed responses, at the end
> the interested user always learns, that it is kinda safe to use the
> highest stable format, even if it is not the default for some strange
> reasons. :)

Oh, the reason is not strange: compatibility concerns are real.  If
using a certain format will force many of that repository's users to
upgrade their own bzr, then it must be done with caution.

Hmm.  How about a concrete proposal:

One strategy is to make the default format always be something that is
compatible with the majority of Bazaars out in the wild.  This might be
one or two formats behind the latest and technically "best" format.

The reasoning behind this is that one can assume a certain rate of
spread for bzr following a release: there are probably still people
using bzr 1.6, but hopefully very few people are using, say, bzr 1.1!

To use this strategy, one usually looks at what versions of bzr are
packaged with major distributions (Ubuntu, Fedora, etc) and at how long
those distributions have been out.  So for example, if Ubuntu 8.10 is
current, and you know that Bazaar X.Y is packaged with it, then that's
one more reason keep the default format something that's compatible with
X.Y's default format... until a newer Ubuntu has been out with a higher
Bazaar, say X.Y+1, for long enough that now in Bazaar X.Z we can switch
the default format to the highest format supported by X.Y+1.

Or is that the strategy Bazaar is currently using?