Package::locator attempts to answer the question: "where a distribution that will provide this package?" the answer is divined by searching the indexes for one or more cpan-like repositories. if you also provide a specific version number, package::locator will attempt to find a distribution with that version of the package, or higher. you can also ask to find the latest version of a package across all the indexes.

package::locator only looks at the index files for each repository, and those indexes only contain information about the latest versions of the packages within that repository. so package::locator is not backpan magic -- you cannot use it to find precisely which distribution a particular package (or file) came from.