Looks like you're not skipping the tests if Test::Warn isn't installed (i mean, warning_like is a Test::Warn function and should be skipped if loading Test::Warn doesn't succeed)

update:

Note you (probably) should use skip blocks to skip tests in Test::More:

SKIP: {
  skip "For some reason",$number_of_tests;
  # tests to skip here
}
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