Cannot run snippets with old Scala versions 2.13.x (like 2.13.0)

[geny200]

Describe the bug

Can't run snippet with old Scala versions 2.13.x (earlier 2.13.18)

Scastie snippet link

https://scastie.scala-lang.org/A8FXxhNkSnKquVYHMARGBg

To Reproduce

1. Go to https://scastie.scala-lang.org
2. Write any scala code (ex: println("Hello world"))
3. Click on 'Build Settings'
4. Change Scala version to 2.13.0
5. Go back to editor and click on 'Run'

Expected behavior

I expected that if scastie allows you to select an old version of Scala, then it will allow you to run it.

Screenshot ( Optional )

Version

Scastie website

What browsers are you seeing the problem on?

Chrome

Relevant log output

java.lang.RuntimeException: expected `scastie12263281932432705226/scalaVersion` to be "2.13.18" or later,
but found "2.13.0"; upgrade scalaVersion to fix the build.

to support backwards-only binary compatibility (SIP-51),
the Scala 2.13 compiler cannot be older than scala-library on the
dependency classpath.
see `scastie12263281932432705226/evicted` to know why scala-library 2.13.18 is getting pulled in.

	at scala.sys.package$.error(package.scala:30)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$14(Defaults.scala:1209)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$14$adapted(Defaults.scala:1198)
	at scala.Option.foreach(Option.scala:407)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$12(Defaults.scala:1198)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$12$adapted(Defaults.scala:1196)
	at scala.collection.Iterator.foreach(Iterator.scala:943)
	at scala.collection.Iterator.foreach$(Iterator.scala:943)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1431)
	at scala.collection.IterableLike.foreach(IterableLike.scala:74)
	at scala.collection.IterableLike.foreach$(IterableLike.scala:73)
	at scala.collection.AbstractIterable.foreach(Iterable.scala:56)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$11(Defaults.scala:1196)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$11$adapted(Defaults.scala:1195)
	at scala.Option.foreach(Option.scala:407)
	at sbt.Defaults$.$anonfun$scalaInstanceFromUpdate$1(Defaults.scala:1195)
	at scala.Function1.$anonfun$compose$1(Function1.scala:49)
	at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:63)
	at sbt.std.Transform$$anon$4.work(Transform.scala:69)
	at sbt.Execute.$anonfun$submit$2(Execute.scala:283)
	at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:24)
	at sbt.Execute.work(Execute.scala:292)
	at sbt.Execute.$anonfun$submit$1(Execute.scala:283)
	at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
	at sbt.CompletionService$$anon$2.call(CompletionService.scala:65)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:840)

[tgodzik]

Looks like an issue with something added to the project dependencies. If we add to a project with Scala version lower such as 2.13.0 and pull a library compiled with 2.13.18 this error will pop up. Not sure where we add the libraries though.

[geny200]

If we add to a project with Scala version lower such as 2.13.0 and pull a library compiled with 2.13.18 this error will pop up

Yes, it's. But in my snippet I don't add any dependency)

[warcholjakub]

Afaik runtime-scala module that is included with the snippets is compiled for 2.13.18 (when the chosen Scala version is 2.13.X). So that'd be the cause.

[tgodzik]

Ideally we should use runtime-scala compiled with 2.13.0 or use older versions for older Scala versions. So essentially have a map <scala_version> -> <last_compiled_version_for_that_scala_version>

[warcholjakub]

The latter approach seems more ideal to me, but after some tries I couldn't make it work, because of some troubles with crosscompiling. I have a working fix using the first approach (but I was worried it would potentially break something tbh).

[tgodzik]

after some tries I couldn't make it work, because of some troubles with crosscompiling

what kinds of problems? Maybe I can help?

[warcholjakub]

For some reason when crosscompiling for two different 2.13 versions, there wasn't two different artifacts published (2.13.0 and 2.13.18 for example) - just one for 2.13. It's the same problem I struggled with in this PR #1054. And after some trying I came to the conclusion that if the first approach works, then it is not worth the effort (but I may be mistaken).

[tgodzik]

And after some trying I came to the conclusion that if the first approach works, then it is not worth the effort (but I may be mistaken).

Yeah, totally