When building with `DEBUG_SMARTLIST`: ``` src/or/routerlist.c:2767:45: warning: cast from function call of type 'int' to non-matching type 'double' [-Wbad-function-cast] return ((double)n_with_descs) / (double)smartlist_len(sl); ^~~~~~~~~~~~~~~~~ 1 warning generated. ``` ``` src/or/routerlist.c:2767:45: warning: cast from function call of type 'int' to non-matching type 'double' [-Wbad-function-cast] return ((double)n_with_descs) / (double)smartlist_len(sl); ^~~~~~~~~~~~~~~~~ 1 warning generated. ```