Scala 3.8.x started to publish its own scala-library, and stopped using Scala 3.13.x:

• Using a Scala 2.13.x library in a Scala 3 subproject is still supported in 3.8.x.
• Using a Scala >= 3.8.x library in a Scala 2.13 subproject is no longer supported.

This is because TASTy Reader on the Scala 2.13 will not be supported for the newer Scala 3.8.x features, and future Scala 3.x releases.

Error state: scala-reflect 3.8.0 not found

If you try to use libraries that are published on Scala 3.8.x or above from a Scala 2.13 subproject, you might run into an error that looks as follows:

[info] Resolved foo_2.13 dependencies
[warn] 
[warn]  Note: Unresolved dependencies path:
[error] stack trace is suppressed; run last foo / update for the full output
[error] (foo / update) sbt.librarymanagement.ResolveException: Error downloading org.scala-lang:scala-reflect:3.8.0
[error]   Not found
[error]   Not found
[error]   not found: /Users/xxx/.ivy2/local/org.scala-lang/scala-reflect/3.8.0/ivys/ivy.xml
[error]   not found: https://repo1.maven.org/maven2/org/scala-lang/scala-reflect/3.8.0/scala-reflect-3.8.0.pom
[error] Total time: 0 s

The fix would be to stay on Scala 3.7.x libraries, or migrate to Scala 3.x.

See also

• https://contributors.scala-lang.org/t/sbt-1-12-1-and-unmoored-scala-reflect-scala-compiler-issue/