Invalid tar.gz created when there is a unicode filename

[vti]

When building a distribution with a unicode filename inside a .tar.gz is created but when unpacking:

tar: Skipping to next header
tar: Child returned status 1
tar: Error is not recoverable: exiting now

Removing the unicode file fixes the problem.

[skaji]

As mentioned in #228, I don't think minil should support such distributions.

OTOH, it could be nice if minil emits some helpful warnings then.

[vti]

Strange, I sometimes have unicode files for testing for example.

[karenetheridge]

Non-ascii characters in filenames in cpan distributions "should" be okay, as long as they are not files that get installed (lib/.pm, bin/ etc), because we do not know what kind of filesystem the user will be installing on. However, Test::Portability has a more limited character set that it checks for, to handle ideosyncracies on various filesystems. Also see the Acme-LookOfDisapproval distribution for pitfalls arising from special characters in .pm files.

[skaji]

@karenetheridge Thanks for clarifying the current status of CPAN distributions which have non-ascii characters in their filenames.
It's very helpful.