Try the technique listed here in its original context. Basically, you can try this:

use ExtUtils::Installed;

my $inst = ExtUtils::Installed->new();

my @missing = $inst->validate("File::BaseName");
# note the improper capitalization

print @missing;
[download]

In this case, the @missing array shows:

File::BaseName is not installed...
[download]

The validate method returns a list of the missing files. Some of the other methods could help, too.