Don't use posix_spawn for commands that need to be put into foreground to avoid a race

Fix for race where a command's output may not be fully drained

postfork.cpp

@@ -386,6 +386,7 @@ bool fork_actions_make_spawn_properties(posix_spawnattr_t *attr, posix_spawn_fil
         // means that the process becomes its own
         // group leader, which is what set_child_group did
         // in this case. So we want this to be 0 if j->pgid is 0.
+        //if (!j->pgid) j->pgid = getpid();
         desired_parent_group_id = j->pgid;
     }