Set length of abbreviated commit id in git describe

[lbulej]

This seems to be needed because the command (as used in various scripts) suddenly started returning commit id with one extra
character, resulting in a mismatch between git describe and the git-described version produced by the sbt-git plugin (at least on my machine with git 2.31.1). Due to this, the pre-push readme check fails to find the right JAR and aborts the push.

[vhotspur]

Perhaps it would make sense to ensure (enforce) that the same length is always used by sbt-git too (and upgrading the length to 12 to make it last virtually forever).

git.useGitDescribe := false

git.formattedShaVersion := {
  val describedVersion = git.gitDescribedVersion.value.getOrElse("")
  val describedVersionNoHash = describedVersion.substring(0, describedVersion.lastIndexOf("-"))
  val shortCommitSha = git.gitHeadCommit.value.getOrElse("").substring(0, 7)
  val suffix = git.makeUncommittedSignifierSuffix(git.gitUncommittedChanges.value, git.uncommittedSignifier.value)
  git.gitHeadCommit.value map { _ => s"${describedVersionNoHash}-g${shortCommitSha}${suffix}" }
}

[lbulej]

Perhaps it would make sense to ensure (enforce) that the same length is always used by sbt-git too (and upgrading the length to 12 to make it last virtually forever).

It surely would, but looking into sbt-git code did not reveal an abbrev-like setting that I could use easily, without having to experiment with SBT tasks :-) What you propose looks fine and can go right in even though I would like it better as a sbt-git setting.

[vhotspur]

I would like it better as a sbt-git setting.

Same here. I only found sbt/sbt-git#155 (from 2018) and the code above was a mix of existing sbt-git source code and other fragments from GitHub. It looks ugly but I doubt there is a better way (because describedVersion is never constructed from parts as it comes from the command itself or from JGit).

[lbulej]

I would like it better as a sbt-git setting.

... (because describedVersion is never constructed from parts as it comes from the command itself or from JGit).

This is why I did not originally understand why the pre-commit hook was failing. I always assumed that sbt-git just gives me the output of git describe, so even if git suddenly started using more characters, sbt-git should just pass it on. It took me a while to discover it, because the difference in one character in the JAR file name was barely discernible and I saw what I expected to see :-) I didn't find anything immediately amiss in sbt-git and did not dig into JGit.