Small envForLambda() fix.

All tests are passing now, though there may still be a small leak.

src/env.c

@@ -103,7 +103,7 @@ struct Environment envForLambda(const Object* params, const Object* arg_forms, i
     }
 
     struct Environment env = {
-        .outer = outer,
+        .outer = NULL,
         .table = buildTable(4),
         .refs = 1,
     };
@@ -125,6 +125,7 @@ struct Environment envForLambda(const Object* params, const Object* arg_forms, i
         cleanObject(&newEnvObj);
         march = march ? march->forward : NULL;
     }
+    env.outer = outer;
 
     return env;
 }