Comment 11 for bug 162954

Yes, you're right. There is a bit more required to trigger this error.

Actually, a ~/.ctypes file is required which is read when calling the ctypes-read-file function.

Here is a minimal one which triggers the error:

>>>>
;; This file has been automatically generated by the Emacs package `ctypes'.
;; Please use the `ctypes-read-file' to load it.

(ctypes-set-types 'c-mode '("foo"))

(ctypes-set-types 'c++-mode 'nil)
<<<<

Btw, I've tested it using a fresh jaunty installation.