Re: Updated Sourceware infrastructure plans

[Joseph Myers <josmyers@redhat.com>]

On Mon, 22 Apr 2024, Mark Wielaard wrote:

> >   A system that uses git as the source of 
> > truth for all the pull request data and has refs through which all this 
> > can be located (with reasonably straightforward, documented formats for 
> > the data, not too closely tied to any particular implementation of a 
> > pull-request system), so that a single clone --mirror has all the data, 
> > might be suitable (people have worked on ensuring git scales well with 
> > very large numbers of refs, which you'd probably get in such a system 
> > storing all the data in git);
> 
> Yes, git is pretty nice for storing lots of variants of somewhat
> identical sources/texts. But this also seems to imply that when we
> offer a system to store "contributor" git trees/forks of projects to
> easily create "pull requests" then we can never remove such users/forks
> and must disallow rebasing any trees that have been "submitted".

For example, GitHub has some version of the source branch for a pull 
request under refs/pull/ in the target respository - that doesn't rely on 
the source branch or repository staying around.  However, that's only one 
version - it doesn't work so well when the source branch is rebased 
(though GitHub itself is reported to keep all forks of a repository in a 
single repository internally, rarely garbage collected, so the previous 
versions probably remain there, just not accessible from any ref).  But 
you could certainly have a convention for ref naming that ensures all 
versions of a PR are available even when it's rebased.  Things like the 
"git evolve" proposal <https://lwn.net/Articles/914041/> could also be 
relevant (maybe that particular proposal wasn't intended for the goal of 
ensuring all submitted versions of a change remain permanently available, 
but at least it's dealing with a similar problem - and the more you have a 
standard way of representing this kind of information in git, rather than 
something very specific to a particular system built on top of git, the 
better).

-- 
Joseph S. Myers
josmyers@redhat.com