I will at least be adding a tag with a version number

hoping to start changing that perception in the community soon :)

Here’s what we have at work, to be able to use it via -X:

(try
    (let [{:keys [fail error]}
          (runner/test
           (cond-> options
             nsrx ; need to turn strings into regexes:
             (assoc :namespace-regex (into #{} (map re-pattern) nsrx))))]
      (System/exit (if (zero? (+ fail error)) 0 1)))
    (finally
      ;; Only called if `test` raises an exception
      (shutdown-agents)))

(defn test
  "Invoked via exec-fn (-X) and accepts the same options that Cognitect's
  test-runner uses:

  * :dir -- set of directories containing tests
  * :namespace -- set of namespaces to test
  * :namespace-regex -- set of regex strings to match namespaces
  * :var -- set of fully qualified symbols to run tests on
  * :include -- set of test metadata keywords to filter on
  * :exclude -- set of test metadata keywords to exclude

  Mimics part of test-runner's -main function regarding
  exit code and shutdown."
  [{nsrx :namespace-regex :as options}]

thx

What’s the benefit of -X when -M have all the equivalent functionality?

Some people prefer one over the other, so now you can choose

A concrete benefit : main opts do not merge, exec args do. So you can use different aliases and combine arguments. We leverage that at work. You can't combine main opts like that.

I see. Thanks.