From 370d483a0d347bcc2455c61a2ba425d01d5483b4 Mon Sep 17 00:00:00 2001
From: "(cdep)illabout" <cdep.illabout@gmail.com>
Date: Mon, 21 Oct 2019 13:45:34 -0400
Subject: [PATCH] libusb1: enable compiling with musl

libusb1 can't depend on systemd in order to be compiling with musl,
because systemd can't be built with musl.

Since systemd provides udev, udev support needs to be disabled when
building libusb1.
---
 .../development/libraries/libusb1/default.nix | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/libraries/libusb1/default.nix b/pkgs/development/libraries/libusb1/default.nix
index 19a8025359a0..9a08a7756c84 100644
--- a/pkgs/development/libraries/libusb1/default.nix
+++ b/pkgs/development/libraries/libusb1/default.nix
@@ -1,4 +1,14 @@
-{ stdenv, fetchurl, pkgconfig, systemd ? null, libobjc, IOKit, withStatic ? false }:
+{ stdenv
+, fetchurl
+, pkgconfig
+, enableSystemd ? stdenv.isLinux && !stdenv.hostPlatform.isMusl
+, systemd ? null
+, libobjc
+, IOKit
+, withStatic ? false
+}:
+
+assert enableSystemd -> systemd != null;
 
 stdenv.mkDerivation (rec {
   pname = "libusb";
@@ -13,12 +23,17 @@ stdenv.mkDerivation (rec {
 
   nativeBuildInputs = [ pkgconfig ];
   propagatedBuildInputs =
-    stdenv.lib.optional stdenv.isLinux systemd ++
+    stdenv.lib.optional enableSystemd systemd ++
     stdenv.lib.optionals stdenv.isDarwin [ libobjc IOKit ];
 
   NIX_LDFLAGS = stdenv.lib.optionalString stdenv.isLinux "-lgcc_s";
 
-  preFixup = stdenv.lib.optionalString stdenv.isLinux ''
+  configureFlags =
+    # We use `isLinux` here only to avoid mass rebuilds for Darwin, where
+    # disabling udev happens automatically. Remove `isLinux` at next big change!
+    stdenv.lib.optional (stdenv.isLinux && !enableSystemd) "--disable-udev";
+
+  preFixup = stdenv.lib.optionalString enableSystemd ''
     sed 's,-ludev,-L${systemd.lib}/lib -ludev,' -i $out/lib/libusb-1.0.la
   '';