>>355
ここに書き込む前に、perldocを嫁
If using crypt on a Unicode string (which potentially has characters with
codepoints above 255), Perl tries to make sense of the situation by
trying to downgrade (a copy of) the string back to an eight-bit byte string
before calling crypt (on that copy). If that works, good.
If not, crypt dies with Wide character in crypt .

おそらく、crypt はPOSIXの仕様に合わせているから、こうなるのではないかと思う。