A try of mesh-controller kept 'PASS' as its only failure: the package's test
program stopped after printing PASS and the package-level failure took its
first line. Now a failure that is not one test's assertion names the tests that
were running and carries the panic line (a timeout's with its running tests),
a signal or fatal error line, a build's first error, or words saying the
program exited during which tests or after they passed; go test's summary lines
are never kept. Tests from captured go test -json of eight real failures
(1901/AC4).