diff -urN gdb.a/gdb/darwin-nat.c gdb.b/gdb/darwin-nat.c
--- gdb.a/gdb/darwin-nat.c	2018-12-22 23:51:54.000000000 -0600
+++ gdb.b/gdb/darwin-nat.c	2019-03-11 15:31:04.000000000 -0500
@@ -1132,7 +1132,7 @@
 			      res, wstatus);
 
 	      /* Looks necessary on Leopard and harmless...  */
-	      wait4 (inf->pid, &wstatus, 0, NULL);
+	      wait4 (inf->pid, &wstatus, WNOHANG, NULL);
 
 	      inferior_ptid = ptid_t (inf->pid, 0, 0);
 	      return inferior_ptid;