gnu: Add emacs-epkg.

* gnu/packages/emacs.scm (emacs-epkg): New public variable.

gnu/packages/emacs.scm

@@ -7819,3 +7819,47 @@ on what kind of objects can be stored; it isn't intended to store arbitrary
 objects.  All objects have to share a common superclass and subclasses cannot
 add any additional instance slots.")
     (license license:gpl3)))
+
+(define-public emacs-epkg
+  ;; The release version is to old for the current database scheme.
+  (let ((commit "432312b9583ed7b88ad9644fd1bf2183765a892e"))
+    (package
+      (name "emacs-epkg")
+      (version (git-version "3.0.0" "1" commit))
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/emacscollective/epkg.git")
+               (commit commit)))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32
+           "0d882kahn7a0vri7a9r15lvmfx1zn2hsga6jfcc6jv0hqbswlb2k"))))
+      (build-system emacs-build-system)
+      (propagated-inputs
+       `(("emacs-closql" ,emacs-closql)
+         ("emacs-dash" ,emacs-dash)))
+      (home-page "https://emacsmirror.net")
+      (synopsis "Browse the Emacsmirror package database")
+      (description "This package provides access to a local copy of the
+Emacsmirror package database.  It provides low-level functions for querying
+the database and a @file{package.el} user interface for browsing the database.
+Epkg itself is not a package manager.
+
+Getting a local copy:
+
+@example
+git clone https://github.com/emacsmirror/epkgs.git ~/.emacs.d/epkgs
+cd ~/.emacs.d/epkgs
+git submodule init
+git config --global url.https://github.com/.insteadOf git@@github.com:
+git submodule update
+@end example
+
+Some submodule may be missing.  In this case Git will prompt for a GitHub user
+name and password.  To skip it press a @key{Return} key.
+
+You could get a Epkg package list by invoking @code{epkg-list-packages} in
+Emacs.")
+      (license license:gpl3+))))