`GenBCode` uses `withCurrentUnit` many times for a unit

[retronym]

try   { withCurrentUnit(item.cunit)(visit(item)) }

for each item populated by:

    override def apply(cunit: CompilationUnit): Unit = {

      def gen(tree: Tree) {
        tree match {
          case EmptyTree            => ()
          case PackageDef(_, stats) => stats foreach gen
          case cd: ClassDef         =>
            q1 add Item1(arrivalPos, cd, cunit)
            arrivalPos += 1
        }
      }

      gen(cunit.body)
    }

This leads to noisy repeated log messages under -Ydebug -verbose (as noticed by @som-snytt.

Not sure whether there are other, less benign problems. But I would recommend reducing the granularity of items to the compilation unit level.