Subject: bug#12548: 24.2.50; Eager macro-expansion skipped due to cycle

From: Stefan Monnier <[email-masked]>
Date: Tue, 02 Oct 2012 21:41:54 -0400

> Compiling emacs-lisp/ert-x.el
> Warning: Eager macro-expansion skipped due to cycle:
>     => (load "gv.el") => (macroexpand-all (defun gv--defun-declaration
>     )) => (macroexpand (pcase  )) => (load "pcase.el") =>
>     (macroexpand-all (defmacro pcase-let  )) => (macroexpand (dolist  ))
>     => (load "gv.el")

I think this is the problem due to "loading cl.el causes pcase's use of
dolist to load cl-macs, which loads gv, which loads pcase, ...".
The occurrence of this problem depends on when pcase gets byte-compiled
(since pcase.elc does not require macroexpansion of dolist).

The best fix I can think of is to ban cl.el's dolist, but I have the
strange feeling this suggestion is not going to fly.

> PPS does using the ellipsis character add anything?

As compared to using "..."?  It's more concise.
As compared to not writing it at all, the advantage is that it preserves
the Elisp syntax, making the result more clear.

        Stefan