tests-extra: improve error output if libknot not usable

tests-extra/runtests.py

@@ -312,6 +312,12 @@ def main(args):
     log.info("KNOT TESTING SUITE %s" % today)
     log.info("Working directory %s" % outs_dir)
 
+    try:
+        import dnstest.libknot
+    except Exception as e:
+        log.error(str(e))
+        sys.exit(1)
+
     ref_time = datetime.datetime.now().replace(microsecond=0)
 
     if params.jobs > 1: # Multi-thread run

tests-extra/tools/dnstest/libknot.py

@@ -12,5 +12,5 @@ try:
     import libknot.control
     import libknot.probe
     libknot.Knot(params.libknot_lib)
-except:
-    raise Skip("libknot not available or set KNOT_TEST_LIBKNOT to another libknot without ASAN")
+except Exception as e:
+    raise Skip("libknot error (%s)" % str(e))