Improve warning "No namespace detected" for files with hidden packages

[dolmen]

When ones want to hide a package from indexing using the package \n Foo; trick, those files are reported as "No namespace detected". This is correct, but the impression the message gives is that is an error that has to be fixed while this is in fact exactly what the author wants. This is somewhat a kind of false positive that may be confusing for other contributors to that project.

It would be more useful to report that the file has namespaces, but that they are explicitely hidden, and may be report this only while in verbose/debug mode.

See also dagolden/Dist-Zilla-Plugin-BumpVersionAfterRelease#7 that is somewhat related.

[kentfredric]

This is slightly challenging to do, for the layer I'm at, I'm simply using Module::Metadata to determine namespace existence and not.

Module::Metadata is what is responding to the package \n Foo trick, and so that conclusion is squirrelled away from me prior to it being something I can check for.

I'd gladly fix this if there's a viable workaround though, I'd just need to know how to do so reliably.

[kentfredric]

https://rt.cpan.org/Ticket/Display.html?id=101439

[dolmen]

Fixed in e6ee0ca