use dontBuild instead of hacks

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

pkgs/development/libraries/fmod/4.24.16.nix

@@ -29,11 +29,10 @@ stdenv.mkDerivation rec {
 
   dontStrip = true;
   dontPatchELF = true;
+  dontBuild = true;
 
   makeFlags = [ "DESTLIBDIR=$(out)/lib" "DESTHDRDIR=$(out)/include" ];
 
-  buildPhase = "true";
-
   preInstall = ''
     mkdir -p $out/lib
   '';

pkgs/development/libraries/fmod/default.nix

@@ -18,7 +18,8 @@ stdenv.mkDerivation rec {
   };
 
   dontStrip = true;
-  buildPhase = "true";
+  dontBuild = true;
+
   installPhase = ''
     mkdir -p $out/lib $out/include/fmodex
 

pkgs/development/libraries/libspotify/default.nix

@@ -1,7 +1,7 @@
 { stdenv, fetchurl, libspotify, alsaLib, readline, pkgconfig, apiKey, unzip, gnused }:
 
-let 
-  version = "12.1.51"; 
+let
+  version = "12.1.51";
   isLinux = (stdenv.system == "x86_64-linux" || stdenv.system == "i686-linux");
 in
 
@@ -29,13 +29,8 @@ else stdenv.mkDerivation {
     else
       null;
 
-  # common
-  buildPhase = "true";
-  # no patch or build phase for darwin
-  phases = 
-    [ "unpackPhase" ] ++ 
-    (stdenv.lib.optionals (isLinux) [ "patchPhase" "buildPhase" ]) ++
-    [ "installPhase" ];
+  dontBuild = true;
+
   installPhase = if (isLinux)
     then "installPhase"
     else ''
@@ -48,7 +43,7 @@ else stdenv.mkDerivation {
       mkdir -p "$out"/share/man
       mv -v man3 "$out"/share/man
     '';
- 
+
 
   # darwin-specific
   buildInputs = stdenv.lib.optional (stdenv.system == "x86_64-darwin") unzip;

pkgs/development/libraries/uthash/default.nix

@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     sha256 = "035z3cs5ignywgh4wqxx358a2nhn3lj0x1ifij6vj0yyyhah3wgj";
   };
 
-  buildPhase = ":";
+  dontBuild = false;
 
   buildInputs = stdenv.lib.optional doCheck perl;
 

pkgs/development/libraries/xlibs-wrapper/default.nix

@@ -2,9 +2,12 @@
 
 stdenv.mkDerivation {
   name = "xlibs-wrapper";
-  buildPhase = "true";
+
+  dontBuild = true;
+
   installPhase = "mkdir -p $out";
   unpackPhase = "sourceRoot=.";
+
   propagatedBuildInputs = packages;
 
   preferLocalBuild = true;