Yes, I know the purpose of AUTOMATED_TESTING, so my post was not as clear as it should have been. Let me clarify the point I'm trying to make with a specific example. Suppose, as a CPAN author, I've written a long-running stress test, t/stress.t say, for my distribution. With AUTOMATED_TESTING, the test writer is expected to write some (imperative) code in t/stress.t to check for the AUTOMATED_TESTING (and possibly other) environment variable/s and skip the test if this variable is not set.

Instead of asking the test to check its runtime environment, I'm proposing that the test tool/s check the test metadata. In this example, the t/stress.t test (declaratively) states, via test metadata, that it is a long-running stress test. Armed with this metadata, the CPAN tool chain can hopefully "do the right thing": "make test" run by a human would skip the test, while automated smoke testers would cheerfully run it.

While the details are yet to be fleshed out, I find this approach attractive for three reasons:

• Easier for test writers. Declarative trumps imperative. For example, the stress test writer does not need to write any (imperative) code to check for any environment variable/s; instead he/she simply states (declaratively) that this is a long-running stress test. Moreover, as environment variables (such as AUTOMATED_TESTING) change over time (with new ones added or old ones removed), the test scripts must be updated in-step.
• Environment variables are a generally unattractive mechanism because they are an OS-level (potentially insecure) global variable that may not be available in all environments that Perl may want to run in. (Update: in some environments the global AUTOMATED_TESTING environment variable may already be taken).
• Using metadata offers interesting extension possibilities in that being a long-running, stress test is just one of many possible test attributes. We may uncover many other useful test attributes if we think about it and once we have a mechanism to describe test metadata.

Update: If you squint, you'll see that the xt/ sub-directory (for "extra" tests) is just a special case of my more general proposal; that is, placing a test in the xt/ sub-directory states (declaratively) that this test has metadata of being an "extra test" (where I guess "extra test" here means "do not run via 'make test' action").