From be33b546725f2cac82251870b452091ab6c89831 Mon Sep 17 00:00:00 2001
From: Erik Arvstedt <erik.arvstedt@gmail.com>
Date: Thu, 10 Sep 2020 10:27:21 +0200
Subject: [PATCH] maintainers/build: skip packages that don't evaluate

---
 maintainers/scripts/build.nix | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/maintainers/scripts/build.nix b/maintainers/scripts/build.nix
index 9b2bf00c803a..bc4355d0aa8e 100644
--- a/maintainers/scripts/build.nix
+++ b/maintainers/scripts/build.nix
@@ -13,8 +13,12 @@ let
           let
             result = builtins.tryEval
               (
-                if pkgs.lib.isDerivation pkg && cond name pkg
-                then [ (return name pkg) ]
+                if pkgs.lib.isDerivation pkg && cond name pkg then
+                  # Skip packages whose closure fails on evaluation.
+                  # This happens for pkgs like `python27Packages.djangoql`
+                  # that have disabled Python pkgs as dependencies.
+                  builtins.seq pkg.outPath
+                    [ (return name pkg) ]
                 else if pkg.recurseForDerivations or false || pkg.recurseForRelease or false
                 then packagesWith cond return pkg
                 else [ ]