Doing e.g.,
  perl -C -MText::Unidecode -we 'for(0x1317..0x2319){printf
  "%04x|%s|%s\n",$_,chr,unidecode chr}'
will expose several
  Use of uninitialized value in substitution iterator at
  /usr/share/perl5/Text/Unidecode.pm line 40.

Probably happens only where the user shouldn't be probing, but still happens.