Re^3: Error running prove "Archive is not a known format type! at /usr/lib/perl5/5.8.8/App/Prove.pm line 538."

[Anonymous Monk]

so it has to be the TAP Formatter

No. Looks like it its from https://metacpan.org/source/WONKO/TAP-Harness-Archive-0.14/lib/TAP/Harness/Archive.pm

        # if it's not a format we understand, or it's not a directory
        $class->_croak("Archive is not a known format type!")
          unless $format && $ARCHIVE_TYPES{$format};
my (%ARCHIVE_TYPES, @ARCHIVE_EXTENSIONS);
BEGIN {
    %ARCHIVE_TYPES = (
        'tar'    => 'tar',
        'tar.gz' => 'tar.gz',
        'tgz'    => 'tar.gz',
    );
    @ARCHIVE_EXTENSIONS = map { ".$_" } keys %ARCHIVE_TYPES;
}

So its your xargs invocatio or its the extra -a/--archive option you're not showing

[kamal]

as you can see i dont have the -a, or --archive option set, in :

find test/ -name '*.t' ! -name '*falcon*' | xargs prove -r test/ -form
+atter=TAP::Formatter::JUnit | tee test_results.xml

[Anonymous Monk]

Then its the other thing :)