subtest failures are reported twice

[tamird]

In short, a failing subtest produces a failure message for itself as well as its parent. This is problematic when e.g. using automation to file issues as we do in CockroachDB, because it results in two issues for a single failure.

A possible solution is to introduce a configuration option in the parser that only reports failures in "leaf" tests.

See cockroachdb/cockroach#12444.

[tebeka]

Thanks for reporting. Will try to work on it this week.