Note that my recommended solution is for a test library to create a report file with a test-report-op (that always succeeds at creating a report file, but the report file may indicate failure), and the test-op just depends on the test-report-op, and signals and error if it didn't indicate success.
What branch of the ASDF repository is this in? These are the only two mentions of test-report-op in master:
There is no branch of ASDF doing this, and so far as I know you don't need one: just define your own subclass of system for which test-op has a suitable method. And if you're using my advanced proposal and the inherited methods don't suit you, just skip the (call-next-method).
I do not understand how test-report-op would help in making a generic version of the test script I posted: https://gitlab.common-lisp.net/uri-template/uri-template2/blob/master/run-te...
The two are orthogonal. What test-report-op would do is help avoid re-testing systems that haven't changed, if and when you do massive incremental testing of lots of systems.
Your script looks mostly good. I would use lisp-invocation instead of ros, but I can see merit to ros, too.
—♯ƒ • François-René Rideau The state is the coldest of all cold monsters. Coldly it lies, too; and this lie creeps from its mouth: "I, the state, am the people." — Nietzsche