fails:Proc#to_s for a proc created with Proc.new returns a description optionally including file and line number
fails:Proc#to_s for a proc created with lambda returns a description including '(lambda)' and optionally including file and line number
fails:Proc#to_s for a proc created with proc returns a description optionally including file and line number
fails:Proc#to_s for a proc created with UnboundMethod#to_proc returns a description including '(lambda)' and optionally including file and line number
