From 7cc40e15e46033924d9d141b3869a94d9d31a973 Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Fri, 28 Feb 2020 12:04:10 -0500
Subject: [PATCH] treewide/nixos: use stdenv.cc.libc instead of glibc when
 available
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This prevents duplication in cross-compiled nixos machines. The
bootstrapped glibc differs from the natively compiled one, so we get
two glibc’s in the closure. To reduce closure size, just use
stdenv.cc.libc where available.
---
 nixos/modules/config/networking.nix    |  2 +-
 nixos/modules/services/system/nscd.nix | 12 ++++++++----
 pkgs/top-level/unix-tools.nix          |  4 ++--
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/nixos/modules/config/networking.nix b/nixos/modules/config/networking.nix
index dd36696b94d..03944de8249 100644
--- a/nixos/modules/config/networking.nix
+++ b/nixos/modules/config/networking.nix
@@ -197,7 +197,7 @@ in
 
       } // optionalAttrs (pkgs.stdenv.hostPlatform.libc == "glibc") {
         # /etc/rpc: RPC program numbers.
-        rpc.source = pkgs.glibc.out + "/etc/rpc";
+        rpc.source = pkgs.stdenv.cc.libc.out + "/etc/rpc";
       };
 
       networking.proxy.envVars =
diff --git a/nixos/modules/services/system/nscd.nix b/nixos/modules/services/system/nscd.nix
index e11f7e049d8..af26dd84707 100644
--- a/nixos/modules/services/system/nscd.nix
+++ b/nixos/modules/services/system/nscd.nix
@@ -7,6 +7,10 @@ let
   nssModulesPath = config.system.nssModules.path;
   cfg = config.services.nscd;
 
+  nscd = if pkgs.stdenv.hostPlatform.libc == "glibc"
+         then pkgs.stdenv.cc.libc.bin
+         else pkgs.glibc.bin;
+
 in
 
 {
@@ -59,16 +63,16 @@ in
         # files. So prefix the ExecStart command with "!" to prevent systemd
         # from dropping privileges early. See ExecStart in systemd.service(5).
         serviceConfig =
-          { ExecStart = "!@${pkgs.glibc.bin}/sbin/nscd nscd";
+          { ExecStart = "!@${nscd}/sbin/nscd nscd";
             Type = "forking";
             DynamicUser = true;
             RuntimeDirectory = "nscd";
             PIDFile = "/run/nscd/nscd.pid";
             Restart = "always";
             ExecReload =
-              [ "${pkgs.glibc.bin}/sbin/nscd --invalidate passwd"
-                "${pkgs.glibc.bin}/sbin/nscd --invalidate group"
-                "${pkgs.glibc.bin}/sbin/nscd --invalidate hosts"
+              [ "${nscd}/sbin/nscd --invalidate passwd"
+                "${nscd}/sbin/nscd --invalidate group"
+                "${nscd}/sbin/nscd --invalidate hosts"
               ];
           };
       };
diff --git a/pkgs/top-level/unix-tools.nix b/pkgs/top-level/unix-tools.nix
index 56bab2fe411..cdad9de61f4 100644
--- a/pkgs/top-level/unix-tools.nix
+++ b/pkgs/top-level/unix-tools.nix
@@ -66,12 +66,12 @@ let
       linux = pkgs.utillinux;
     };
     getconf = {
-      linux = if stdenv.hostPlatform.libc == "glibc" then pkgs.glibc
+      linux = if stdenv.hostPlatform.libc == "glibc" then pkgs.stdenv.cc.libc
               else pkgs.netbsd.getconf;
       darwin = pkgs.darwin.system_cmds;
     };
     getent = {
-      linux = if stdenv.hostPlatform.libc == "glibc" then pkgs.glibc
+      linux = if stdenv.hostPlatform.libc == "glibc" then pkgs.stdenv.cc.libc
               else pkgs.netbsd.getent;
       darwin = pkgs.netbsd.getent;
     };