[perl #117097] [BUG] say $!.WHAT fails in CATCH block

[Christian Bartolomaeus via RT]

There was a short discussion on #perl6 about this recently: 
http://irclog.perlgeek.de/perl6/2015-11-17#i_11554013

ZoffixW         How come $! is empty?
                m: my ( $v1, $op, $v2 ) = (2, '-', "zoffix"); my $x = try { 
EVAL "$v1 $op $v2"; CATCH { fail "Invalid operand to Color: Got error $!" } }; 
say $x
camelia         rakudo-moar a662e0: OUTPUT«Use of Nil in string context  in 
block  at /tmp/Dg9t65PMrW:1␤===SORRY!===␤Invalid operand to Color: Got error ␤»
* ZoffixW       is going by http://learnxinyminutes.com/docs/perl6/ that $! 
should contain the error message in that case
                Um. never mind.
psch            m: my ( $v1, $op, $v2 ) = (2, '-', "zoffix"); my $x = try { 
EVAL "$v1 $op $v2"; }; say $!
camelia         rakudo-moar a662e0: OUTPUT«5===SORRY!5=== Error while compiling 
/home/camelia/EVAL_0␤Undeclared routine:␤    zoffix used at line 1␤␤»
* ZoffixW       is really lost
psch            $! is set after the CATCH, inside you get $_
                not sure if that's correct though, but it's what's impl'd
ZoffixW         Ah, thanks psch++