fuzz: test_runner: Better error message when built with afl

test/fuzz/test_runner.py

@@ -72,11 +72,13 @@ def main():
         logging.error("No fuzz targets selected")
     logging.info("Fuzz targets selected: {}".format(test_list_selection))
 
+    try:
         help_output = subprocess.run(
             args=[
                 os.path.join(config["environment"]["BUILDDIR"], 'src', 'test', 'fuzz', test_list_selection[0]),
                 '-help=1',
             ],
+            timeout=1,
             check=True,
             stderr=subprocess.PIPE,
             universal_newlines=True,
@@ -84,6 +86,9 @@ def main():
         if "libFuzzer" not in help_output:
             logging.error("Must be built with libFuzzer")
             sys.exit(1)
+    except subprocess.TimeoutExpired:
+        logging.error("subprocess timed out: Currently only libFuzzer is supported")
+        sys.exit(1)
 
     run_once(
         corpus=args.seed_dir,