From b78025586b5b28043c8db40b9ed250b245edc2d6 Mon Sep 17 00:00:00 2001
From: Will Dietz <w@wdtz.org>
Date: Tue, 23 Jan 2018 15:42:02 -0600
Subject: [PATCH 1/2] busybox: don't use utmp/wtmp on musl since they won't
 work anyway

https://wiki.musl-libc.org/faq.html#Q:-Why-is-the-utmp/wtmp-functionality-only-implemented-as-stubs?
---
 pkgs/os-specific/linux/busybox/default.nix | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/pkgs/os-specific/linux/busybox/default.nix b/pkgs/os-specific/linux/busybox/default.nix
index a8d5ab48ac21..e35c50450539 100644
--- a/pkgs/os-specific/linux/busybox/default.nix
+++ b/pkgs/os-specific/linux/busybox/default.nix
@@ -1,11 +1,13 @@
 { stdenv, lib, buildPackages, fetchurl, fetchpatch
 , enableStatic ? false
 , enableMinimal ? false
-, useMusl ? false, musl
+, useMusl ? stdenv.hostPlatform.libc == "musl", musl
 , extraConfig ? ""
 , buildPlatform, hostPlatform
 }:
 
+assert stdenv.hostPlatform.libc == "musl" -> useMusl;
+
 let
   configParser = ''
     function parseconfig {
@@ -24,6 +26,10 @@ let
     }
   '';
 
+  libcConfig = lib.optionalString useMusl ''
+    CONFIG_FEATURE_UTMP n
+    CONFIG_FEATURE_WTMP n
+  '';
 in
 
 stdenv.mkDerivation rec {
@@ -69,6 +75,7 @@ stdenv.mkDerivation rec {
 
     ${extraConfig}
     CONFIG_CROSS_COMPILER_PREFIX "${stdenv.cc.targetPrefix}"
+    ${libcConfig}
     EOF
 
     make oldconfig

From 329db7b49053245875e79fbc3dbe26755759dce8 Mon Sep 17 00:00:00 2001
From: Will Dietz <w@wdtz.org>
Date: Tue, 23 Jan 2018 15:42:36 -0600
Subject: [PATCH 2/2] busybox: bump copybuf 4kB -> 64kB

---
 pkgs/os-specific/linux/busybox/default.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/os-specific/linux/busybox/default.nix b/pkgs/os-specific/linux/busybox/default.nix
index e35c50450539..5a485cdcf9fe 100644
--- a/pkgs/os-specific/linux/busybox/default.nix
+++ b/pkgs/os-specific/linux/busybox/default.nix
@@ -73,6 +73,9 @@ stdenv.mkDerivation rec {
     # Set paths for console fonts.
     CONFIG_DEFAULT_SETFONT_DIR "/etc/kbd"
 
+    # Bump from 4KB, much faster I/O
+    CONFIG_FEATURE_COPYBUF_KB 64
+
     ${extraConfig}
     CONFIG_CROSS_COMPILER_PREFIX "${stdenv.cc.targetPrefix}"
     ${libcConfig}