> checkOpts -feature -unchecked
> compile

# same-file edit, as in lichess-org/lila project/BuildSettings.scala
$ copy-file changes/B1.scala project/B1.scala
> reload
> checkOpts -feature -deprecation -Werror -unchecked
-> compile

# separate-file edit: only B2.scala changes, B1.scala is untouched
$ copy-file changes/B2.scala project/B2.scala
> reload
> checkOpts -feature -deprecation -Werror -unchecked -explain
