From @tadzik

$ cat test.pl
sub MAIN(@​args where sub { False }) {
  say "​:)"
}

$ perl6 test.pl
Usage​:
  test.pl <args>

$ cat test.pl # note the slurpy
sub MAIN(*@​args where sub { False }) {
  say "​:)"
}

$ perl6 test.pl
Constraint type check failed for parameter '@​args'
  in sub MAIN at test.pl line 1
  in block <unit> at test.pl line 1

I expect USAGE in both cases, since it's both exactly invalid use of MAIN.
Patch and spectest incoming.

From @tadzik

https://github.com/rakudo/rakudo/tree/rt-127977 contains a fix for that

On 24/04/16 12​:28, perl6 via RT wrote​:

Greetings,

This message has been automatically generated in response to the
creation of a trouble ticket regarding​:
"[BUG] Constraint on a slurpy MAIN parameter leaks out internal exceptions",
a summary of which appears below.

There is no need to reply to this message right now. Your ticket has been
assigned an ID of [perl #​127977].

Please include the string​:

      \[perl #​127977\]

in the subject line of all future correspondence about this issue. To do so,
you may reply to this message.

                     Thank you,
                     perl6\-bugs\-followup@​perl\.org

-------------------------------------------------------------------------
$ cat test.pl
sub MAIN(@​args where sub { False }) {
say "​:)"
}

$ perl6 test.pl
Usage​:
test.pl <args>

$ cat test.pl # note the slurpy
sub MAIN(*@​args where sub { False }) {
say "​:)"
}

$ perl6 test.pl
Constraint type check failed for parameter '@​args'
in sub MAIN at test.pl line 1
in block <unit> at test.pl line 1

--------------------------------------------------

I expect USAGE in both cases, since it's both exactly invalid use of MAIN.
Patch and spectest incoming.

From @usev6

For the records​: There is a test for this ticket (currently fudged 'todo') in S06-other/main-usage.t

From @zoffixznet

The test now passes. It was fixed today by one of these commits​: rakudo/rakudo@774e2de...41b685e

Not sure which exactly, I only I ran spectest ~10 hours ago and the TODO test wasn't passing.

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

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