Debug compiler version

Author: liufengyun

compiler/src/dotty/tools/dotc/config/Feature.scala

@@ -115,6 +115,7 @@ object Feature:
 
   /** Check that experimental compiler options are only set for snapshot or nightly compiler versions. */
   def checkExperimentalFlags(using Context): Unit =
+    println(Properties.versionString)
     if !experimentalEnabled then
       val features = ctx.settings.language.value.filter { feature =>
         feature.contains(nme.experimental.toString) && !feature.contains("macros")