No docs on how to specify the main class for project

[arbitrary-dev]

steps

https://github.com/scala/scala-lang/issues/1287

$ sbt new scala/scala3.g8
$ sbt run
[info] welcome to sbt 1.4.5 (Gentoo Java 11.0.10)
[info] loading settings for project global-plugins from deps.sbt,scalafmt.sbt ...
[info] loading global plugins from /home/man/.sbt/1.0/plugins
[info] loading project definition from /home/man/projects/scala3-sample/project
[info] set current project to scala3-sample (in build file:/home/man/projects/scala3-sample/)
[error] java.lang.RuntimeException: No main class detected.
[error]     at scala.sys.package$.error(package.scala:30)
[error] stack trace is suppressed; run last Compile / bgRun for the full output
[error] (Compile / bgRun) No main class detected.
[error] Total time: 0 s, completed Oct 27, 2021, 12:53:18 PM

problem

Were unable to find in https://www.scala-sbt.org/1.x/docs/Running.html or elsewhere there information on how to properly specify the main class.

expectation

I go to https://www.scala-sbt.org/1.x/docs/Running.html and it's day clear how to specify the main class to be able to sbt run.

notes

:(

[arbitrary-dev]

The original issue was due to not following the go to the generated folder instruction.

Still no easy way to find out in docs, how to specify defferent main class.

Especially for Scala 3 which have main functions:

@main def hello: Unit =