No need for the top-level implicit resort task.

src/cell.c

@@ -2406,7 +2406,6 @@ void cell_activate_star_formation_tasks(struct cell *c, struct scheduler *s) {
 
   /* Activate the star formation task */
   scheduler_activate(s, c->hydro.star_formation);
-  scheduler_activate(s, c->hydro.stars_resort);
 
   /* Shallow tree case -> the resort task is at this level */
   if (c->hydro.super == c) {
@@ -2418,7 +2417,6 @@ void cell_activate_star_formation_tasks(struct cell *c, struct scheduler *s) {
 
     for (int k = 0; k < 8; ++k) {
       if (c->progeny[k] != NULL) {
-        message("hello");
         scheduler_activate(s, c->progeny[k]->hydro.stars_resort);
       }
     }

src/engine_maketasks.c

@@ -1000,9 +1000,6 @@ void engine_make_hierarchical_tasks_hydro(struct engine *e, struct cell *c,
         c->hydro.stars_resort = scheduler_addtask(
             s, task_type_stars_resort, task_subtype_none, 0, 0, c, NULL);
         scheduler_addunlock(s, c->hydro.star_formation, c->hydro.stars_resort);
-      } else {
-        c->hydro.stars_resort = scheduler_addtask(
-            s, task_type_stars_resort, task_subtype_none, 0, 1, c, NULL);
       }
     }
   }
@@ -1018,7 +1015,6 @@ void engine_make_hierarchical_tasks_hydro(struct engine *e, struct cell *c,
 
       scheduler_addunlock(s, c->top->hydro.star_formation,
                           c->hydro.stars_resort);
-      scheduler_addunlock(s, c->hydro.stars_resort, c->top->hydro.stars_resort);
     }
   }
 
@@ -1111,7 +1107,8 @@ void engine_make_hierarchical_tasks_hydro(struct engine *e, struct cell *c,
         scheduler_addunlock(s, c->stars.stars_out, c->super->timestep);
 
         if (with_star_formation && c->hydro.count > 0) {
-          scheduler_addunlock(s, c->top->hydro.stars_resort, c->stars.stars_in);
+          scheduler_addunlock(s, star_resort_cell->hydro.stars_resort,
+                              c->stars.stars_in);
         }
       }