Problem when startup when include package with MELPA

[casouri]

Issue

Warning (initialization): An error occurred while loading ‘/Users/yuan/.emacs.d/init.el’:

Invalid slot type: cfgl-package, :location, (satisfies (lambda (x) (or (stringp x) (memq x (quote (built-in local site elpa))) (and (listp x) (eq (quote recipe) (car x)))))), melpa

Show up when start up.

Symptom

I created my private layer casouri under ~/.emacs.d/private/casouri/

If I include package with MELPA

such as

(defconst casouri-packages
  '(
    ;; Nyan cat in modeline
    (nyan-mode :location melpa))

Emacs broke as described.

If I change MEPLA to EPLA

such as

(defconst casouri-packages
  '(
    ;; Nyan cat in modeline
    (nyan-mode :location elpa))

Emacs runs without any error.

Other info

macOS Sierra 10.12.5
Emacs 25.2

Full package.el

;;; packages.el --- casouri layer packages file for Spacemacs.
;;
;; Copyright (c) 2012-2017 Sylvain Benner & Contributors
;;
;; Author: Yuan Fu <yuan@missSilver>
;; URL: https://github.com/syl20bnr/spacemacs
;;
;; This file is not part of GNU Emacs.
;;
;;; License: GPLv3

;;; Commentary:

;; See the Spacemacs documentation and FAQs for instructions on how to implement
;; a new layer:
;;
;;   SPC h SPC layers RET
;;
;;
;; Briefly, each package to be installed or configured by this layer should be
;; added to `casouri-packages'. Then, for each package PACKAGE:
;;
;; - If PACKAGE is not referenced by any other Spacemacs layer, define a
;;   function `casouri/init-PACKAGE' to load and initialize the package.

;; - Otherwise, PACKAGE is already referenced by another Spacemacs layer, so
;;   define the functions `casouri/pre-init-PACKAGE' and/or
;;   `casouri/post-init-PACKAGE' to customize the package as it is loaded.

;;; Code:

(defconst casouri-packages
  '(
    ;; Nyan cat in modeline
    (nyan-mode :location elpa))

  ;; Examples:
  ;;
  ;; Get the package from MELPA, ELPA, etc.
  ;; some-package
  ;; some-package :location elpa)

  ;; A local package
  ;; (some-package :location local)

  ;; A package recipe
  ;; (some-package :location (recipe
  ;;                         :fetcher github
  ;;                         :repo "some/repo"))
  ;;
  ;; An excluded package
  ;; (some-package :excluded t)
  )
(defun casouri/init-nyan-mode ()
  (use-package nyan-mode)
  :defer
  :config
  (setq nyan-animate-nyancat t)
  (setq nyan-wavy-trail t)
  )

;;; packages.el ends here

Question

Does anyone knows what is the problem? I have searched Google but had no luck.
Thanks.

P.S.: I know I can add the single package to additional package, but I want to put all personal configured package into one layer for easier management.

[d12frosted]

From what I see, the supported value is elpa, which means that it will install package using package-install from... well, ELPA, MELPA or Org ELPA. It seems that documentation is misleading. You can't pin packages to specific archive an such a way 😿

But there is a good new - #6575 allows it 😸

[casouri]

This works! Thanks👍