1 files changed, 3 insertions, 0 deletions
diff --git a/vm.c b/vm.c
index 6084f21..39bf65d 100644
--- a/vm.c
+++ b/vm.c
@@ -100,6 +100,9 @@ int runvm(State *S) {
 			}
 			Val v = ht_get(S, &S->globals, AS_STRING(varname));
 			PUSH(v);
+			if (IS_NIL(v)) {
+				printf("warning: nil global read %s\n", AS_CSTRING(varname));
+			}
 			break;
 		}
 		case OP_SETGLOBAL: {