* lisp/emacs-lisp/package-vc.el (package-vc--unpack): Create a dummy
descriptor if PKG-DESC is nil.
how to fetch and build the package. See `package-vc--archive-spec-alist'
for details. The optional argument REV specifies a specific revision to
checkout. This overrides the `:branch' attribute in PKG-SPEC."
+ (unless pkg-desc
+ (package-desc-create :name (car pkg-spec) :kind 'vc))
(pcase-let* (((map :lisp-dir) pkg-spec)
(name (package-desc-name pkg-desc))
(dirname (package-desc-full-name pkg-desc))