Closes #1319 Report git-hash used to package the distribution in REPL

[krasinski]

• Adds SBT BuildInfoPlugin to know git-hash in runtime
• Reports git-hash in REPL

[felixmulder]

Hi @krasinski, thanks for the PR. It looks like you're hitting a CI oddity. A rebuild should fix it.

Cheers,
Felix

[felixmulder]

/rebuild

[felixmulder]

Hi again @krasinski - so I've looked over your code and it solves the problem quite elegantly. But there is a caveat. When we're bootstrapping, we don't want to depend on a specific build tool for two reasons.

1. When doing the bootstrap we want complete control over the classpath and as such usually perform this straight from the command line without invoking sbt (in the future, yes we should have a mechanism for doing the bootstrap with a well guarded classpath in sbt)
2. Dotty might be compiled with alternative build-tools in the near future (i.e. not sbt)

Therefore I believe it best to go for a solution that does not depend on sbt or provides a default if the plugin has not created the BuildInfo file. If you can provide a fallback - then we're happy to accept this PR.

Cheers,
Felix

[krasinski]

I will try to do this in another way - by storing the git-hash in manifest file and then reading it back in runtime.

[krasinski]

Hi @felixmulder, I pushed the new solution, can you review?

[felixmulder]

LGTM, great job @krasinski !