Output filename is .yaml (since it is YAML).

galaxy.cpp

@@ -308,7 +308,7 @@ void Galaxy::add_port(port p) {
 
 void Galaxy::load(void) {
   std::string filename =
-      str(boost::format("galaxy-%1%-%2%.json") % game % username);
+      str(boost::format("galaxy-%1%-%2%.yaml") % game % username);
   // reset ?
   meta = YAML::Node();
   config = YAML::Node();
@@ -376,7 +376,7 @@ void Galaxy::load(void) {
 
 void Galaxy::save(void) {
   std::string filename =
-      str(boost::format("galaxy-%1%-%2%.json") % game % username);
+      str(boost::format("galaxy-%1%-%2%.yaml") % game % username);
   YAML::Node data;
   // add some information to meta before saving.
   meta["save_to"] = filename;