From @AlexDaniel

Code​:
loop (my $i = 0; $i <= 5; $i++;) { say }

Result​:
===SORRY!=== Error while compiling ./test.pl
Missing block
at ./test.pl​:2
------> loop (my $i = 0; $i <= 5; $i++⏏;) { say }

This error message could be better. Currently it is a bit confusing and
makes me want to do this​:
loop (my $i = 0; $i <= 5; $i++ { say };) { say }

===SORRY!=== Error while compiling ./test.pl
Unexpected block in infix position (missing statement control word before
the expression?)
at ./test.pl​:2
------> loop (my $i = 0; $i <= 5; $i++⏏ { say };) { say }
  expecting any of​:
  infix
  infix stopper

STD does a much better job at detecting the actual problem and says
"Malformed loop spec" – now that's awesome.

IRC log​: http://irclog.perlgeek.de/perl6/2015-07-10#i_10879185

From @masak

alex (>)​:

Code​:
loop (my $i = 0; $i <= 5; $i++;) { say }

Result​:
===SORRY!=== Error while compiling ./test.pl
Missing block
at ./test.pl​:2
------> loop (my $i = 0; $i <= 5; $i++⏏;) { say }

Interesting failure mode.

That semicolon looks unnecessary but harmless to me. (It's of the "statement-ending" kind, not the "statement-separating" kind that Perl usually uses.) I wonder if it couldn't be possible to parse it correctly, but warn about "useless semicolon".

As a further data point, Perl 5 also parsefails on the corresponding code​:

$ perl -Mstrict -wE'for (my $i = 0; $i < 10; $i++;) { say $i }'
syntax error at -e line 1, near "++;"
Execution of -e aborted due to compilation errors.

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

From @jnthn

On Fri Jul 10 17​:06​:45 2015, alex.jakimenko@​gmail.com wrote​:

Code​:
loop (my $i = 0; $i <= 5; $i++;) { say }

Result​:
===SORRY!=== Error while compiling ./test.pl
Missing block
at ./test.pl​:2
------> loop (my $i = 0; $i <= 5; $i++⏏;) { say }

This error message could be better. Currently it is a bit confusing and
makes me want to do this​:
loop (my $i = 0; $i <= 5; $i++ { say };) { say }

===SORRY!=== Error while compiling ./test.pl
Unexpected block in infix position (missing statement control word before
the expression?)
at ./test.pl​:2
------> loop (my $i = 0; $i <= 5; $i++⏏ { say };) { say }
expecting any of​:
infix
infix stopper

STD does a much better job at detecting the actual problem and says
"Malformed loop spec" – now that's awesome.

IRC log​: http://irclog.perlgeek.de/perl6/2015-07-10#i_10879185

Error message now in line with STD, and test added in S32-exceptions/misc.t.

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