Many years ago — but from version-to-version too many of the Scala programs suffered bad bitrot, failed and were not updated.

Scala code is backwards compatible, only the class files are not - so at most dependencies could have become stale. With a recompile, the programs should work just fine.

Requirements changed; and neither the original program contributors or anyone else on the scala mailing list wished to update the programs.

(The scala mailing list archive doesn't seem to go back that far.)