in reply to
Re^2: make test and File::Spec problems
in thread make test and File::Spec problems
When earlier versions of T::H launched external Perl processes in which to run your tests, they unilaterally added the -w flag. That enables warnings globally throughout the entire Perl process, even if the author didn't develop with warnings enabled.
Since the release of Perl 5.6.0 in early 2000, the warnings pragma has had lexical scoping, so that individual modules, files, and scopes can enable or disable warnings on their own.
Something somewhere in File::Spec produces that warning, but no one who's patched that module has felt the need to fix it because it's clearly not an error and it only produces a warning if you ignore lexical warnings.