From adriaan.larmuseau@gmail.com

Bug report #​124393 states that one cannot use stub multi methods in roles,
but multi methods do not work with roles in general.
Consider the following example​:

role A {
  multi method a(Int , Int --> Mu​:D) { False };
  multi method a(Bool​:D $handle, Int $int --> Mu​:D) { False };
}

class Test does A {
  multi method a(Int $stream, Int $int) { True }
  multi method a(Bool​:D $handle, Int $int) { True }
}

# test
my $test = Test.new();
my Bool $b = True;
$test.a($b,5);

Produces the following output​:

Ambiguous call to 'a'; these signatures all match​:
:(Test $​: Bool​:D $handle, Int $int, *%_)
:(Test $​: Bool​:D $handle, Int $int, *%_)
  in block <unit> at test.pl​:17

For perl6 --version​:
This is perl6 version 2015.06-293-g27f88c4 built on MoarVM version
2015.06-98-gf22142b

From @FROGGS

I think it works as designed.

What you seem to want is what class inheritence does.
Roles on the other hand mix their methods into the applied class.
So the class consumes these methods as if they were defined within that class.

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

From @moritz

I agree with Tobias Leich's reasoning. Rejecting ticket.

@moritz - Status changed from 'open' to 'rejected'