Subject: bug#30990: Should the byte compiler warn about :type mismatches?

From: Glenn Morris <[email-masked]>
Date: Thu, 29 Mar 2018 13:11:00 -0400

Alex Branham wrote:

> Would it be possible/desirable to make the byte-compiler warn about
> :type mismatches with defcustoms?

I think that to do this in general requires evaluating the defcustom at
compile time, which probably isn't the right thing.

emacs -batch -l admin/cus-test.el -f cus-test-opts all

will find these mismatches. I think it should be converted to an
(expensive) ert test, which would solve the problem for Emacs itself.