scala 2.12 (https://bugs.debian.org/1149686) replaces scala 2.11 in
unstable. Its scala-library Breaks the 2.11 build of pilon, so pilon needs
a rebuild with versioned dependencies on scala-library.

The fix is in https://salsa.debian.org/med-team/pilon/-/merge_requests/1.
Upload it after scala 2.12 reaches unstable.