[PATCH] kunit: tool: Recommend --raw_output=all if no KTAP found

[David Gow <david@davidgow.net>]

If no KTAP header is found in the kernel output (e.g., because the kernel
crashed before the KUnit executor was run), it's very useful to re-run the
test with --raw_output=all, as that will show any error output (such as a
stacktrace, log message, BUG, etc). This is not particularly intuitive,
however, as --raw_output=all is not well known.

Add an extra log line to advertise --raw_output=all in this case, as it's
a terrible user experience to just get "Did any KUnit tests run?"

Signed-off-by: David Gow <david@davidgow.net>
---
 tools/testing/kunit/kunit_parser.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
index 5338489dcbe4..1c61a0ed740d 100644
--- a/tools/testing/kunit/kunit_parser.py
+++ b/tools/testing/kunit/kunit_parser.py
@@ -857,7 +857,8 @@ def parse_run_tests(kernel_output: Iterable[str], printer: Printer) -> Test:
 	test = Test()
 	if not lines:
 		test.name = '<missing>'
-		test.add_error(printer, 'Could not find any KTAP output. Did any KUnit tests run?')
+		test.add_error(printer, 'Could not find any KTAP output. Did any KUnit tests run?\n' +
+			'Try running with the --raw_output=all option to see any log messages.')
 		test.status = TestStatus.FAILURE_TO_PARSE_TESTS
 	else:
 		test = parse_test(lines, 0, [], False, printer)
-- 
2.53.0