`./bin/dotr -language:Scala2` fails

[Blaisorblade]

It gives

warning: multiple classpaths are found, dotr only use the last one.
Unrecognized option: -language:Scala2
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

while ./bin/dotc -language:Scala2 is fine and ./bin/dotr -repl -language:Scala2 works as well.
Comparing dotc and dotr leads to the differences between dist-bootstrapped/target/pack/bin/dotr and dist-bootstrapped/target/pack/bin/dotc.