From @usev6

There are failing (skipped) tests for rakudo-j in S32-list/unique.t and S32-list/repeated.t that fail with 'This Seq has already been iterated, and its values consumed'. An example​:

$ ./perl6-j -e 'my $a = <b b>; $a .= unique; say $a.perl'
Seq.new-consumed()

As far as I understand, the problem happens because calling the mutator method with '$a .= unique' is executed in sink context. If I wrap that code in nqp​::stmts to avoid sinking it works as expected​:

$ ./perl6-j -e 'use nqp; my $a = <b b>; nqp​::stmts($a .= unique); say $a.perl'
("b",).Seq

I took a look at the implementation of 'p6sink' for JVM and MoarVM and both implementations are calling method sink -- but maybe rakudo-m does not call it directly on the Seq?

From @usev6

On Sun Jul 24 01​:22​:23 2016, bartolin@​gmx.de wrote​:

There are failing (skipped) tests for rakudo-j in S32-list/unique.t
and S32-list/repeated.t that fail with 'This Seq has already been
iterated, and its values consumed'. An example​:

$ ./perl6-j -e 'my $a = <b b>; $a .= unique; say $a.perl'
Seq.new-consumed()

As far as I understand, the problem happens because calling the
mutator method with '$a .= unique' is executed in sink context. If I
wrap that code in nqp​::stmts to avoid sinking it works as expected​:

$ ./perl6-j -e 'use nqp; my $a = <b b>; nqp​::stmts($a .= unique); say
$a.perl'
("b",).Seq

I took a look at the implementation of 'p6sink' for JVM and MoarVM and
both implementations are calling method sink -- but maybe rakudo-m
does not call it directly on the Seq?

Now, this is interesting. The first evaluations works now. Probably it got fixed by one of TimToady++'s recent sink related commits.

$ ./perl6-j -e 'my $a = <b b>; $a .= unique; say $a.perl'
("b",).Seq

But there is another version of that code, that still produces a consumed Seq​:

$ ./perl6-j -e 'my $a = <b b>; $a.=unique; say $a.perl'
Seq.new-consumed()

Looks like '$a.=unique' is parsed differently than '$a .= unique'. (Something with 'dotty' instead of 'infix​: .='.)

@usev6 - Status changed from 'new' to 'open'

From @usev6

The latter example works now as well​:

$ ./perl6-j -e 'my $a = <b b>; $a.=unique; say $a.perl'
$(("b",).Seq)

I've unfudged the skipped tests for this issue and I'm closing this ticket as 'resolved'.

@usev6 - Status changed from 'open' to 'resolved'