Well, you probably don't have unicode inside $var , you're starting with not-unicode, with octets, so can't blame unidecode , you don't have uni

$ perl -E " use Text::Unidecode;  say unidecode( qq{\x4d\x6f\x6e\x74\x
+72\xc3\xa9\x61\x6c} )"
MontrA(c)al

$ perl -E " use Text::Unidecode;  use Encode; say unidecode( decode_ut
+f8( qq{\x4d\x6f\x6e\x74\x72\xc3\xa9\x61\x6c}))"
Montreal
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perlunitut: Unicode in Perl#I/O flow (the actual 5 minute tutorial)