Add #include <unisted.h> for sleep and usleep

pkgs/os-specific/linux/alienfx/default.nix

@@ -14,11 +14,12 @@ stdenv.mkDerivation {
     sha256 = "47501a3b4e08d39edee4cd829ae24259a7e740b9798db76b846fa872989f8fb1";
   };
 
-  patchPhase = ''
+  prePatch = ''
     substituteInPlace Makefile --replace /usr/ $out/
     substituteInPlace Makefile --replace "install -o root -g root" "install"
   '';
  
+  patches = [./unistd.patch];
   buildInputs = [ libusb1 ];
   makeFlags = "build";
   preInstall = ''

pkgs/os-specific/linux/alienfx/unistd.patch

@@ -0,0 +1,12 @@
+diff --git a/alienfx.cpp b/alienfx.cpp
+index 5981039..aea8992 100644
+--- a/alienfx.cpp
++++ b/alienfx.cpp
+@@ -13,6 +13,7 @@
+ #include <string.h>
+ #include <iostream>
+ #include <libusb-1.0/libusb.h>
++#include <unistd.h>
+ 
+ using namespace std;
+