[perl #127041] is looser LTA error if used incorrectly

[via RT]

# New Ticket Created by  Lloyd Fournier 
# Please include the string:  [perl #127041]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=127041 >


21:46 < lizmat> m: sub a is looser {}
21:46 <+camelia> rakudo-moar 7e106c: OUTPUT«===SORRY!=== Error while
compiling /tmp/dyKjMCb7xA␤Can't use unknown
                 trait 'is looser' in a sub declaration.␤at
/tmp/dyKjMCb7xA:1␤    expecting any of:␤        rw raw
                 hidden-from-backtrace hidden-from-USAGE␤        pure
default DEPRECATED i…»
21:47 < llfourn> 'is looser' is actually in that error message which is a
bit LTA :\
21:47 < lizmat> m: sub a is looser(infix:<+>) {}
21:47 <+camelia> rakudo-moar 7e106c: OUTPUT«===SORRY!=== Error while
compiling /tmp/4MtREU_vCv␤Can't use unknown
                 trait 'is looser' in a sub declaration.␤at
/tmp/4MtREU_vCv:1␤    expecting any of:␤        rw raw
                 hidden-from-backtrace hidden-from-USAGE␤        pure
default DEPRECATED i…»
21:48 < lizmat> llfourn: that just means it's not finding the correct MMD
candidate
21:48 < lizmat> llfourn: I suggest you rakudobug it
21:48 < llfourn> lizmat: okie dokes
21:48 < lizmat> m: sub a is looser(&infix:<+>) {}
21:48 <+camelia> rakudo-moar 7e106c: ( no output )
21:49 < llfourn> lizmat: so I'll rakudobug it as an LTA error?
21:49 < lizmat> well, yes, because apparently if you give it a Callable
operator, it does work
21:50 < lizmat> m: sub is looser(&infix:<+>) {}

sub a is looser {} #LTA
sub a is looser(infix:<+>) {} #LTA
sub a is looser(&infix:<+>) {} # works
sub is looser(&infix:<+>) {} #LTA