From @masak

<felher> And now for something completely different​:
<felher> r​: say [[1,2,0]].classify​: -> $rpn { $rpn eqv [1,2,0]|[2,0,1] };
<p6eval> rakudo ed269f​: OUTPUT«Cannot assign to a readonly variable or
a value [...]
<moritz> r​: say [1,2,0] eqv [1,2,0]|[2,0,1]
<p6eval> rakudo ed269f​: OUTPUT«any(True, False)␤»
<moritz> felher​: ah, might be easy to fix
<moritz> maybe just some variable that needs a Mu type instead of Any
<felher> :)
* masak submits rakudobug
<masak> r​: say [[1,2,0]].classify​: -> $rpn { $rpn eqv [1,2,0] }
<p6eval> rakudo ed269f​: OUTPUT«True 1 2 0␤»
<masak> r​: say [1,2,3,4,5].classify​: -> $rpn { $rpn eqv 1|3 }
<p6eval> rakudo ed269f​: OUTPUT«Cannot assign to a readonly variable or
a value [...]
<moritz> r​: say (1, 2).classify​: -> $x { 1|2 }
<p6eval> rakudo ed269f​: OUTPUT«Cannot assign to a readonly variable or
a value [...]
<masak> moritz++
<masak> it's probably returning the junction out of the .classify
block that causes trouble.
<moritz> masak​: correct

From @moritz

What behavior do you expect? I can only fix it if I know what it should
look like after the fix :-)

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

From @masak

On Tue Aug 07 03​:36​:11 2012, moritz wrote​:

What behavior do you expect? I can only fix it if I know what it should
look like after the fix :-)

The immediate expectation is for the error "Cannot assign to a readonly
variable or a value" not to occur. That's the observable -- sorry for
being less-than-clear on that. :)

Then again, I see the problem in deciding what should happen. The
conservative thing would be to have .classify barf on junctions as keys.
Or -- if it makes sense -- have the junction be stringified and use the
string as the key.

From @usev6

Current failure mode​:

$ perl6-m -e 'say (1, 2).classify​: -> $x { 1|2 }'
P6opaque​: no such attribute '$!reified'
  in block <unit> at -e​:1

$ perl6-m --version
This is perl6 version 2015.09-431-g5d83db3 built on MoarVM version 2015.09-79-gee9fc2b

From @dogbert17

On Tue, 20 Oct 2015 23​:06​:02 -0700, bartolin@​gmx.de wrote​:

Current failure mode​:

$ perl6-m -e 'say (1, 2).classify​: -> $x { 1|2 }'
P6opaque​: no such attribute '$!reified'
in block <unit> at -e​:1

$ perl6-m --version
This is perl6 version 2015.09-431-g5d83db3 built on MoarVM version
2015.09-79-gee9fc2b

Things have changed yet again​:

$ perl6-m -e 'say (1, 2).classify​: -> $x { 1|2 }'
{1 => [1 2], 2 => [1 2]}

$ perl6-m -v
This is Rakudo version 2018.06-24-gc441d8d built on MoarVM version 2018.06
implementing Perl 6.c.