From 6555ec03c30fe4221c3de8f6293a3e902c155c4c Mon Sep 17 00:00:00 2001
From: Nikolay Amiantov <ab@fmap.me>
Date: Tue, 21 Mar 2017 19:41:25 +0300
Subject: [PATCH] udev module: filter duplicate udev paths

Fixes #24174
---
 nixos/modules/services/hardware/udev.nix | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
index 028907693a5a..9f42f9e59ad5 100644
--- a/nixos/modules/services/hardware/udev.nix
+++ b/nixos/modules/services/hardware/udev.nix
@@ -35,6 +35,7 @@ let
   udevRules = pkgs.runCommand "udev-rules"
     { preferLocalBuild = true;
       allowSubstitutes = false;
+      packages = unique (map toString cfg.packages);
     }
     ''
       mkdir -p $out
@@ -45,7 +46,7 @@ let
       echo 'ENV{PATH}="${udevPath}/bin:${udevPath}/sbin"' > $out/00-path.rules
 
       # Add the udev rules from other packages.
-      for i in ${toString cfg.packages}; do
+      for i in $packages; do
         echo "Adding rules for package $i"
         for j in $i/{etc,lib}/udev/rules.d/*; do
           echo "Copying $j to $out/$(basename $j)"
@@ -132,10 +133,11 @@ let
   hwdbBin = pkgs.runCommand "hwdb.bin"
     { preferLocalBuild = true;
       allowSubstitutes = false;
+      packages = unique (map toString ([udev] ++ cfg.packages));
     }
     ''
       mkdir -p etc/udev/hwdb.d
-      for i in ${toString ([udev] ++ cfg.packages)}; do
+      for i in $packages; do
         echo "Adding hwdb files for package $i"
         for j in $i/{etc,lib}/udev/hwdb.d/*; do
           ln -s $j etc/udev/hwdb.d/$(basename $j)