new bug with mutation

original commit: b649575afc2611ca0a3bec1f6f3d70e45ec011c1

collects/tests/typed-scheme/xfail/xmodule-mutation.rkt

@@ -0,0 +1,19 @@
+#lang racket/load
+
+(module m typed/racket
+  (: x Any)
+  (define x "foo")
+  (: f (-> Void))
+  (define (f) (set! x 1))
+  (provide f x))
+
+(module n typed/racket
+  (require 'm)
+  (if (string? x)
+      (begin
+        (f)
+        ;; this should be a type error!
+        (string-append x "foo"))
+      0))
+
+(require 'n)