It appears that bb8ba24 merged changes to /ted/test from #6790 and #6896
incorrectly, as the thread no longer compiled.
Because the former PR included the change made to the latter (printing
with slog priority 3 in case of failure), the minimum viable fix is
taking the contents of /ted/test from #6790 and using those as-is.
However, that had hidden success prints behind a "quiet" flag, and
provided no way of configuring that from outside the thread. So
additionally, we expand the ""vase parsing"" performed on the thread's
argument, such that an optional _first_ parameter of a quiet=? may be
passed.
111a21eea7