Install Module::Which and say

$ which_pm Foo::Bar
Foo::Bar             (not found)
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or

$ which_pm DateTime File::Slurp -w 0
DateTime             0.35       /usr/local/lib/perl5/site_perl/5.8.8/c
+ygwin/DateTime.pm
File::Slurp          9999.12    /usr/local/lib/perl5/site_perl/5.8.8/F
+ile/Slurp.pm
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or

$ which_pm Business:: --p5p
Business::BR              0.00_08    at ${installsitelib}/
Business::BR::PIS         0.00_16    at ${installsitelib}/
Business::BR::Ids         0.00_16    at ${installsitelib}/
Business::BR::Biz         0.00_09    at ${installsitelib}/
Business::BR::IE          0.00_16    at ${installsitelib}/
Business::BR::CNPJ        0.00_16    at ${installsitelib}/
Business::BR::CPF         0.00_16    at ${installsitelib}/
Business::BR::Ids::Common 0.00_16    at ${installsitelib}/

from Config:
        installsitelib: /usr/local/lib/perl5/site_perl/5.8.8
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