[11u] Proposal: Switch jdk11u development to Git/Skara with 11.0.13 cycle

[Severin Gehwolf]

On Thu, 2021-02-11 at 17:20 +0000, Andrew Haley wrote:
> On 11/02/2021 16:46, Andrew Dinn wrote:
> > On 11/02/2021 13:46, Andrew Haley wrote:
> > 
> > > It's also important not to consider 11 in isolation: while we do not
> > > need to move 8 and 11 simultaneously, I very much do not want to see
> > > them use different workflows for a long period.
> > I'm also ok with switching jdk11u.
> > 
> > I'm not sure jdk8u will be quite so easy to switch as it is made up of 
> > multiple hg repos. We can just clone these hg repos into their own 
> > separate github repos. However, I'm not sure if the Skara tooling will 
> > 'just work' when we try to relate multiple change sets committed to 
> > these independent repos to common JIRAs.
> 
> We can take input from the Skara folk about that. As I understand
> it, there are already people who have built a monorepo from JDK 8.

Does Skara help for getting a forest into mono-repo shape? For mainline
JDK it was JEP 296 which did it[0]. My understanding is that having a
mono-repo is a requirement for a move to git (using skara tooling). If
that's true, we'd have to be doing something similar for JDK 8u first.
Failing that, we'd have to do a different approach for moving JDK 8u.

Also, do we know how well other efforts of getting the mercurial forest
into a single git tree fares in terms of preserving history?

So while moving JDK 11u over seems doable (already a mono-repo; there
is already a git mirror under the openjdk Github namespace[1]), getting
JDK 8u done seems significanly different and more risky.

With that in mind, should a potential move of 11u to git be (time)
dependent on a move of jdk8u to git? I'm not sure...

Thanks,
Severin

[0] https://openjdk.java.net/jeps/296
[1] https://github.com/openjdk/jdk11u
    https://github.com/openjdk/jdk11u-dev