From @masak

<masak> rakudo​: $_ = 1; .say; .=subst(/(.) $0*/, { $/.chars ~ $0 }, :g); .say
<p6eval> rakudo 1b06df​: OUTPUT«1␤Use of uninitialized value␤Use of
uninitialized value␤0␤»
<masak> I expected that one to say '11' the second time.
<masak> what am I missing?
<pmichaud> I'm not sure.
<masak> rakudo​: $_ = "foo"; say .subst(/o/, { ~$/ }, :g)
<p6eval> rakudo 1b06df​: OUTPUT«foo␤»
<masak> rakudo​: $_ = "foo"; say .=subst(/o/, { ~$/ }, :g)
<p6eval> rakudo 1b06df​: OUTPUT«Use of uninitialized value␤Use of
uninitialized value␤f␤»
* masak submits rakudobug
<TimToady> {} has its own $/ maybe?
<masak> some strange interaction between .= and $/
<masak> TimToady​: that doesn't explain why .subst works above.
<pmichaud> it might be an odd interaction with $_ . Or perhaps with
the way .= has been implemented.

From @cognominal

for 0 { when ARRAY {} }
Missing block at line 1, near "}\n"

The problem : ARRAY is an undefined function.
The message is unhelpful.
Also brain muscles makes type ARRAY for Array pretty easy.

--
cognominal stef

From @bbkr

On Kiev build

[16​:16] <bbkr> rakudo​: $_ = "foo"; say .=subst(/o/, { ~$/ }, :g)
[16​:16] <p6eval> rakudo aa015a​: OUTPUT«fAny()Any()␤»
[16​:17] <bbkr> it above output corect?
[16​:17] <masak> no.
[16​:18] <masak> bbkr​: ~$/ should contain an 'o' in both evaluations of
the closure.
[16​:18] <masak> s/contain/be/

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

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

From @masak

<sjohnson> A tutor who tooted the flute
<sjohnson> Tried to tutor two tooters to toot
<sjohnson> Said the two to the tutor
<sjohnson> "Is it tougher to toot
<sjohnson> Or to tutor two tooters to toot?"
<tadzik> woot
<sjohnson> heh
<masak> nom​: $_ = 'toot'; s/$/er/; .say; s/oo(.)e/u $0 o/; .say
<p6eval> nom 1c2c2d​: OUTPUT«tooter␤tu or␤»
<masak> is that a known/submitted bug?
<[Coke]> when you submit that, you can golf it down to just the 2nd regexp
<masak> of course :)
<masak> nom​: $_ = 'a'; s/(.)/$0/; .say
<p6eval> nom 1c2c2d​: OUTPUT«␤»
* masak submits rakudobug
<masak> sjohnson​: your poem just found us a rakudobug! :)
<sjohnson> nice!

From @moritz

We now have a hackish implementation and a single passing test in
subst.t -- enough for me to close this ticket. Cheers!

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