Transition project Valhalla to git and GitHub

[David Simms]

Hi all,

You might have heard that there is an OpenJDK project named Skara 
evaluating and trialing using Git for OpenJDK and GitHub for hosting the 
repositories [1]. We have been asked to try out Git, GitHub and the 
Skara tooling, as a means of validating, and to provide feedback about 
the Project Skara effort. There is already a number of OpenJDK projects 
using Git, GitHub and Skara:
- OpenJFX
- OpenJMC
- Loom
- Mobile
- Panama (the "foreign" branches)
- Skara

A transition entails switching to Git as an SCM (see the Git manual 
[2]), and the repository would be hosted on GitHub [3]. After the 
transition, the current Mercurial repository would no longer be updated. 
There is currently already a read-only mirror of Valhalla in place [4], 
you can it use to try out Git and some of the tooling, though submitting 
pull requests and pushing will not work (as it is a read-only mirror).

I suggest that project Valhalla transition to git, GitHub and Skara and 
that we set the target date for the transition to around 2 weeks from 
now. How about Monday the 9th of March? I also suggest we adopt GitHub's 
pull request workflow together with the bots from project Skara.

Adopting pull requests and the Skara bots means that the review process 
would work partly through GitHub. In particular, all changes must start 
out as pull requests. Skara automatically generates webrevs, "RFR" 
emails and supports bi-directional syncing between mailing lists and 
GitHub for those that prefer using webrev and the mailing lists. If you 
are unfamiliar with GitHub and pull requests, I suggest checking out 
GitHub's guide [5]. Note that project Skara also provides CLI tools for 
interacting with GitHub for those that prefer working from a terminal. 
You can find more info about these tools on the Skara wiki page [6] or 
from the Skara README [7].

If you have any comments or questions regarding this transition, please 
reply to this thread.

Cheers,
Mr. Simms

[1] : https://openjdk.java.net/jeps/369
[2] : https://git-scm.com/docs/user-manual
[3] : https://github.com/
[4] : https://github.com/openjdk/valhalla
[5] : https://guides.github.com/introduction/flow/
[6] : https://wiki.openjdk.java.net/display/SKARA/Skara
[7] : https://github.com/openjdk/skara