It is always a thrill to see an issue one reports being fixed! And thanks to scala-cli it so very easy to test. I was unsure which nightly to test. So went through latest nightly builds of 3.8, 3.9 and 3.10!!! `Scala 3.10.0-RC1-bin-20260603-466fa59-NIGHTLY` is perhaps not new enough to contain the fix. https://github.com/scala/scala3/issues/25234

#scala

Using language.experimental.subCases interferes with pattern match exhaustivity checking · Issue #25234 · scala/scala3

Compiler version Scala CLI version: 1.12.2 Scala version (default): 3.8.1 Minimized code //> using scala 3.8.1 //> using options -deprecation -feature -Wunused:all -Werror import language.experimen...

GitHub
Yesss! It works as expected with 3.10.0-RC1-bin-20260605-0ef4809-NIGHTLY