add scala 3 release version flag

[i10416]

No description provided.

[i10416]

rel #138

[armanbilge]

Thanks for the PR! :) A few quick notes:

• Actually the compiler flag was renamed to -scala-output-version :)
• Unfortunately, adding the compiler flag is not sufficient; we also need to modify the POM to use the old Scala standard library instead of the new one. Fortunately, sbt 1.7.0 will implement the extra functionality, so we can directly integrate with their setting.
  https://github.com/sbt/sbt/releases/tag/v1.7.0-M1
• I think we should make the default Scala 3.1.1

Also, would you mind targeting your PR at main branch instead of series/0.4? We will release this feature in sbt-typelevel v0.5.0 :)

[i10416]

Hmm, should we wrap scalaOutputVersion := "3.0.2" in tlScalaRelease rather than exposing it to users?

[armanbilge]

That's a good question. I don't think we need our own tlScalaRelease setting. I'm not sure what we would use it for.

[i10416]

Sure.

In addition, are we going to use scalaOutputVersion here, which is still pre-release , or wait for next sbt release?. What do you think?

[armanbilge]

I think it's too hard to support this Scala 3 feature without relying on the sbt integration. So, we definitely need to rely on that scalaOutputVersion setting.

I can't promise I'll merge this PR right away. I have to double-check when the planned release date for sbt v1.7.0 is and and decide whether sbt-typelevel v0.5.0 should wait for it or not. I don't currently feel a big rush to release sbt-typelevel v0.5.0 so that strategy may make sense.

Meanwhile I am publishing some milestone prereleases of sbt-typelevel v0.5.0 so some people can use that with the sbt milestone prerelease, if they want.

[i10416]

Okay. I'm not in a hurry too.
We'd better waiting for sbt 1.7.0 release for v0.5.0. I close this PR for now so that someone desperately needs that feature can feel free to open PR.

[i10416]

@armanbilge Thanks for reviewing :)

[armanbilge]

Thanks for your contribution! :)

[armanbilge]

@i10416 if you're still interested in working on this one, I had an idea for how we can do this so it will be ready before sbt 1.7.0 is released, and also so we don't have to bump to sbt-typelevel 0.5.0.

Basically, the idea is to use sbt "reflection", when you refer to a setting using a String. Here's an example:

sbt-typelevel/sonatype/src/main/scala/org/typelevel/sbt/TypelevelUnidocPlugin.scala

Line 38 in 66b313c

ThisBuild / SettingKey[Option[ModuleID]]("tlSiteApiModule") := Some(projectID.value)

This technique will work even if somebody uses sbt-typelevel with sbt 1.6.x. It won't do anything, but at least it won't crash the build :)

[i10416]

@armanbilge Oh! I didn't know that technique.