> This package seem fine, the email is corresponding to the right PyPI user,
> so I was wondering if this is not a specific server-side issue.

The problem is (apparently) an invalid classifier. Your package version
was not registered, so file upload tried to transparently register it,
which then choked as it couldn';t find one of the classifiers in the
database. I added a validation step now before the actual package
registration, so you should get a more meaningful error message now.

HTH,
Martin