use dontBuild instead of hacks

changes:
 * buildPhase = "true"
 * buildPhase = ":"

pkgs/os-specific/darwin/install_name_tool/default.nix

@@ -5,9 +5,9 @@ assert stdenv.isDarwin;
 stdenv.mkDerivation {
   name = "install_name_tool";
   src = "/usr/bin/install_name_tool";
+
   unpackPhase = "true";
-  configurePhase = "true";
-  buildPhase = "true";
+  dontBuild = true;
 
   installPhase = ''
     mkdir -p "$out"/bin

pkgs/os-specific/darwin/osx-sdk/default.nix

@@ -7,9 +7,8 @@ in stdenv.mkDerivation rec {
 
   src = "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk";
 
-  unpackPhase    = "true";
-  configurePhase = "true";
-  buildPhase     = "true";
+  unpackPhase = "true";
+  dontBuild = true;
 
   installPhase = ''
     mkdir -p $out/Developer/SDKs/

pkgs/os-specific/gnu/hurd/default.nix

@@ -87,7 +87,7 @@ stdenv.mkDerivation ({
 //
 
 (if headersOnly
- then { buildPhase = ":"; installPhase = "make install-headers"; }
+ then { dontBuild = true; installPhase = "make install-headers"; }
  else (if (cross != null)
        then {
          crossConfig = cross.config;

pkgs/os-specific/gnu/libpthread/default.nix

@@ -46,7 +46,7 @@ stdenv.mkDerivation ({
        "ac_cv_lib_ihash_hurd_ihash_create=yes"
      ];
 
-   buildPhase = ":";
+   dontBuild = true;
    installPhase = "make install-data-local-headers";
  }
  else { })

pkgs/os-specific/gnu/mach/default.nix

@@ -53,5 +53,5 @@ stdenv.mkDerivation ({
 //
 
 (if headersOnly
- then { buildPhase = ":"; installPhase = "make install-data"; }
+ then { dontBuild = true; installPhase = "make install-data"; }
  else {}))

pkgs/os-specific/linux/firmware/zd1211/default.nix

@@ -11,9 +11,12 @@ stdenv.mkDerivation rec {
     sha256 = "04ibs0qw8bh6h6zmm5iz6lddgknwhsjq8ib3gyck6a7psw83h7gi";
   };
 
-  buildPhase = "true";
+  dontBuild = true;
 
-  installPhase = "mkdir -p $out/lib/firmware/zd1211; cp * $out/lib/firmware/zd1211";
+  installPhase = ''
+    mkdir -p $out/lib/firmware/zd1211
+    cp * $out/lib/firmware/zd1211
+  '';
 
   meta = {
     description = "Firmware for the ZyDAS ZD1211(b) 802.11a/b/g USB WLAN chip";