From @timo

In this code

role Command {
  method execute { ... }
}

class EchoCommand is Command {
  method execute(Str $echostring) { shell "echo '$echostring'" }
}

gives the following error​:

===SORRY!===
Method 'execute' must be implemented by Command because it is required by a role
at foobar.p6​:6
------>

It would be cool if it would acknowledge, that there is a message, but the
signatures don't match.

From @timo

actually, this happened due to using "is" instead of "does".

Should there be a different error message when making a "class" that "is"
a "role"?

The RT System itself - Status changed from 'new' to 'open'

From @MasterDuke17

Fixed in rakudo/rakudo#1068
Test added in rakudo/rakudo#1070

@MasterDuke17 - Status changed from 'open' to 'resolved'