libmemcached: fix build on darwin

pkgs/by-name/li/libmemcached/libmemcached-fix-linking-with-libpthread.patch

@@ -1,19 +0,0 @@
-diff -up libmemcached-1.0.16/build-aux/ltmain.sh.orig libmemcached-1.0.16/build-aux/ltmain.sh
---- libmemcached-1.0.16/build-aux/ltmain.sh.orig	2013-12-03 16:36:53.222107642 +0100
-+++ libmemcached-1.0.16/build-aux/ltmain.sh	2013-12-03 16:37:35.770132249 +0100
-@@ -5664,6 +5664,15 @@ func_mode_link ()
- 	    *" $arg "*) ;;
- 	    * ) func_append new_inherited_linker_flags " $arg" ;;
- 	esac
-+	# As we are forced to pass -nostdlib to g++ during linking, the option
-+	# -pthread{,s} is not in effect;  add the -lpthread to $deplist
-+	# explicitly to link correctly.
-+	if test "$tagname" = CXX -a x"$with_gcc" = xyes; then
-+	  case "$arg" in
-+	    -pthread*) func_append deplibs " -lpthread" ;;
-+	  esac
-+	fi
-+
- 	continue
- 	;;
- 

pkgs/by-name/li/libmemcached/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch,
   bison,
   cmake,
   flex,
@@ -22,6 +23,15 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-jEw6L2/139oo4sGprl9Xp0DTarxAK1bEF2ak2kHWSAs=";
   };
 
+  patches = lib.optionals stdenv.hostPlatform.isDarwin [
+    (fetchpatch {
+      name = "libcxx-compat.patch";
+      url = "https://github.com/awesomized/libmemcached/commit/547460c12287a34a5993045157a0e13e14203f92.patch";
+      includes = [ "test/lib/random.cpp" ];
+      hash = "sha256-aH51O4UM3M4yzTtC8bTy+6NKrtPfgqysrvspMZ/gWDc=";
+    })
+  ];
+
   nativeBuildInputs = [
     bison
     cmake