class X::Parameter::Placeholder does X::Comp { }

Thrown when a placeholder parameter is used inside a signature where a normal parameter is expected. The reason is often that a named parameter :$param was misspelled as $:param.

For example

sub f($:param) { }

dies with

===SORRY!===
In signature parameter, placeholder variables like $:param are illegal
you probably meant a named parameter: ':$param'

Methods

method parameter

The text of the offensive parameter declaration ($:param in the example above).

method right

Suggestion on how to write the parameter declaration instead (:$param in the example above).