Print error if no test cases are run

test/test_runner.c

@@ -81,6 +81,7 @@ main (int argc, char *argv[])
     }
 
 
+    int number_run;
     int number_failed = 0;
     size_t i;
 
@@ -106,9 +107,12 @@ main (int argc, char *argv[])
         srunner_run(sr, NULL, test_case, CK_VERBOSE);
 #endif
     }
+    number_run = srunner_ntests_run(sr);
     number_failed = srunner_ntests_failed (sr);
     srunner_free (sr);
     
+    if (!number_run)
+        puts("ERROR: no tests were run");
     if (number_failed) 
         printf("ERROR: %d tests failed\n", number_failed);