Question on defoma

I want use defoma to register simsun.ttc
firstly i using "apt-get install defoma x-ccidfont-conf" to install
(when installint defoma , i choose mode "xtt")

after i using defom-hints truetype simsun.ttc > simsun.hints
it prompt me that:
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Wait for second...
Use of uninitialized value in split at /usr/share/defoma/libperl-hint.pl line 59.
Use of uninitialized value in split at /usr/share/defoma/libperl-hint.pl line 59.
Use of uninitialized value in split at /usr/share/defoma/libperl-hint.pl line 59.
defoma-hints Can't locate FreeType.pm in @INC (@INC contains: /usr/local/lib/perl/5.6.1 /usr/local/share/perl/5.6.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.6.1 /usr/share/perl/5.6.1 /usr/local/lib/site_perl .) at (eval 1) line 2.
\n
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Is that i ignore some import package

apt-get install libft-perl