Better tooling for using multirepos

[ErikBjare]

So, I've been thinking a bunch about our multirepo strategy and its gone pretty back and forth.

My thoughts so far:

• Multirepos lead to clearer dependencies/modules/separation of concerns
• You can pretty easily (and cleanly) go from a multirepo to a monorepo. The other way isn't so easy.
• One downside is the increased overhead required (updating submodules in the bundle repo, having to merge multiple inter-dependent PRs from time to time). Not much to do about this that I can see, I think the benefits are worth it so far.
• Lack of good tooling: many are embracing monorepos at large scales (Facebook, Chromium) and that leads to less investment in multirepo tooling.

Tooling to develop:

• [x] Tool to get collect contributor stats across multiple repos (Done! See contributor-stats)
• [x] Tool that generates diffs and/or get a list of added commits (and their messages) in submodules between bundle-repo commits. This would help greatly with making changelogs.
  • This apparently existed in git, who knew!

This is just some thoughts I wanted to get out there, I think the multirepo/monorepo discussion is an interesting configuration management issue and I definitely want to learn more.

[ErikBjare]

I've done some more reading on git subrepo (here's a good introduction) and getting increasingly optimistic about it.

Would have to try it out to see if it's as good as it seems.

Edit: I don't think we'll use it. submodule works good enough and has good support. I also discovered that Qt5 uses submodules.

[ErikBjare]

I just realized that git submodule summary exists.

With it you can even do git submodule summary <commit> to get a list of all commits in submodules since some commit/tag. Very useful to be able to do things like git submodule summary v0.7.0b1.

[ErikBjare]

Closing since the tasks are done. I'm still thinking about the pros and cons, but lets settle this for now.

[ErikBjare]

Holy shit, just found out about this gem from an article: git config --global status.submoduleSummary true

With it you get nice submodule info whenever you git status. No idea how I could have missed it.