With httpie 0.8.0 the HTTP method has to come after the auth argument.

docs/tutorial/4-authentication-and-permissions.md

@@ -206,7 +206,7 @@ If we try to create a snippet without authenticating, we'll get an error:
 
 We can make a successful request by including the username and password of one of the users we created earlier.
 
-    http POST -a tom:password http://127.0.0.1:8000/snippets/ code="print 789"
+    http -a tom:password POST http://127.0.0.1:8000/snippets/ code="print 789"
 
     {
         "id": 5,