From 7f7252093ffdd080d0e3f3faa7a4a9ccda51e616 Mon Sep 17 00:00:00 2001
From: adisbladis <adisbladis@gmail.com>
Date: Sun, 9 Jan 2022 12:20:41 +1300
Subject: [PATCH] emacs.pkgs.melpa*: Fix version numbers with negative numbers

---
 .../editors/emacs/elisp-packages/libgenerated.nix            | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkgs/applications/editors/emacs/elisp-packages/libgenerated.nix b/pkgs/applications/editors/emacs/elisp-packages/libgenerated.nix
index 8ecce11a7421..d49e18c8a3e0 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/libgenerated.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/libgenerated.nix
@@ -69,7 +69,10 @@ in {
           melpaBuild {
             inherit pname ename commit;
             version = if isNull version then "" else
-              lib.concatStringsSep "." (map toString version);
+              lib.concatStringsSep "." (map toString
+                # Hack: Melpa archives contains versions with parse errors such as [ 4 4 -4 413 ] which should be 4.4-413
+                # This filter method is still technically wrong, but it's computationally cheap enough and tapers over the issue
+                (builtins.filter (n: n > 0) version));
             # TODO: Broken should not result in src being null (hack to avoid eval errors)
             src = if (isNull sha256 || broken) then null else
               lib.getAttr fetcher (fetcherGenerators args sourceArgs);