1 files changed, 7 insertions, 2 deletions
diff --git a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
index 1e9a8191b3f16..00646b6d81b38 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
@@ -23,6 +23,11 @@ formats commits for you.
 
 */
 
+let
+  # Read ./recipes-archive-melpa.json in an outer let to make sure we only do this once.
+  defaultArchive = builtins.fromJSON (builtins.readFile ./recipes-archive-melpa.json);
+in
+
 { lib, pkgs }: variant: self:
 let
   dontConfigure = pkg:
@@ -57,7 +62,7 @@ let
     if pkg != null then dontConfigure (externalSrc pkg pkgs.rtags)
     else null;
 
-  generateMelpa = lib.makeOverridable ({ archiveJson ? ./recipes-archive-melpa.json
+  generateMelpa = lib.makeOverridable ({ archiveJson ? defaultArchive
                                        }:
     let
       inherit (import ./libgenerated.nix lib self) melpaDerivation;
@@ -66,7 +71,7 @@ let
           (s: s != null)
           (map
             (melpaDerivation variant)
-            (lib.importJSON archiveJson)
+            (if builtins.isList archiveJson then archiveJson else lib.importJSON archiveJson)
           )
         )
       );