We also require that directories can be searched, so make that explicit

This is a requirement of fopen()

examples/main.c

@@ -387,11 +387,12 @@ int main(int argc, char *argv[]) {
 #endif
 
   /* Check that we can write the snapshots by testing if the output
-   * directory exists and is writable. */
+   * directory exists and is searchable and writable. */
   char basename[PARSER_MAX_LINE_SIZE];
   parser_get_param_string(params, "Snapshots:basename", basename);
   const char *dirp = dirname(basename);
-  if (access(dirp, W_OK) != 0) {
+  message("dirp = %s", dirp);
+  if (access(dirp, W_OK|X_OK) != 0) {
       error("Cannot write snapshots in directory %s (%s)", dirp,
             strerror(errno));
   }