In string, @%s now must be written as \@%s
           (F) It used to be that Perl would try to guess whether
           you wanted an array interpolated or a literal @.  It
           did this when the string was first used at runtime.
           Now strings are parsed at compile time, and ambiguous
           instances of @ must be disambiguated, either by
           prepending a backslash to indicate a literal, or by
           declaring (or using) the array within the program
           before the string (lexically).  (Someday it will
           simply assume that an unbackslashed @ interpolates an
           array.)