fails:String#unpack with format 'M' calls #to_str to coerce the directives string
fails:String#unpack with format 'M' decodes an empty string
fails:String#unpack with format 'M' decodes the complete string ignoring newlines when given a single directive
fails:String#unpack with format 'M' appends empty string to the array for directives exceeding the input size
fails:String#unpack with format 'M' ignores the count or '*' modifier and decodes the entire string
fails:String#unpack with format 'M' decodes the '=' character
fails:String#unpack with format 'M' decodes an embedded space character
fails:String#unpack with format 'M' decodes a space at the end of the pre-encoded string
fails:String#unpack with format 'M' decodes an embedded tab character
fails:String#unpack with format 'M' decodes a tab character at the end of the pre-encoded string
fails:String#unpack with format 'M' decodes an embedded newline
fails:String#unpack with format 'M' decodes pre-encoded byte values 33..60
fails:String#unpack with format 'M' decodes pre-encoded byte values 62..126
fails:String#unpack with format 'M' decodes pre-encoded byte values 0..31 except tab and newline
fails:String#unpack with format 'M' decodes pre-encoded byte values 127..255
fails:String#unpack with format 'm' calls #to_str to coerce the directives string
fails:String#unpack with format 'm' decodes an empty string
fails:String#unpack with format 'm' decodes the complete string ignoring newlines when given a single directive
fails:String#unpack with format 'm' ignores the count or '*' modifier and decodes the entire string
fails:String#unpack with format 'm' appends empty string to the array for directives exceeding the input size
fails:String#unpack with format 'm' decodes all pre-encoded ascii byte values
fails:String#unpack with format 'm' produces binary strings
