REPL runner command line options weakly parsed

[som-snytt]

minimized code

I was tripped up by -cp not meaning -classpath. Also by -help not offering any.

➜  dotr -classpath /tmp/stuff f
OK
➜  dotr -cp /tmp/stuff f       
Error: Unable to initialize main class f
Caused by: java.lang.NoClassDefFoundError: scala/util/CommandLineParser$ParseError
➜  dotr -help
Starting dotty REPL...
scala>                                                                                                                     
➜  dotr -version
Starting dotty REPL...
Dotty compiler version 0.21.0-RC1 -- Copyright 2002-2019, LAMP/EPFL
scala>                 

Or maybe it does mean some kind of classpath, because that looks like it found the entry point but nothing else. This is finding nothing, or not finding anything:

➜  dotr -classpath junk nada
Error: Could not find or load main class nada
Caused by: java.lang.ClassNotFoundException: nada

Compilation output

As per transcript.

expectation

Common options explained by dotr -help. Most people won't use it at the shell or sbt prompt anyway.

OK, it just completed in sbt, where it looks like options are passed on to java. So -cp must be fielded by java, explaining the result above.

[retronym]

I just ran into this. The runner passes options other than {-repl, -run, -classpath, -with-compiler, -d, -J*}, directly to the JVM as residual_args. The JVM accepts -cp as alias for -cp and this ovewrwrites the setting of "-classpath \"$cp_arg\"" which includes the standard library.

[retronym]

Taking the step of accepting the -cp alias in #11366