Add support for building cargo'ed Rust programs

pkgs/development/tools/build-managers/cargo/common.nix

@@ -3,6 +3,16 @@
 {
   inherit version;
 
+  name = "cargo-${version}";
+
+  postInstall = ''
+    rm "$out/lib/rustlib/components" \
+       "$out/lib/rustlib/install.log" \
+       "$out/lib/rustlib/rust-installer-version" \
+       "$out/lib/rustlib/uninstall.sh" \
+       "$out/lib/rustlib/manifest-cargo"
+  '';
+
   platform = if stdenv.system == "i686-linux"
     then "i686-unknown-linux-gnu"
     else if stdenv.system == "x86_64-linux"
@@ -20,5 +30,5 @@
     platforms = platforms.linux;
   };
 
-  name = "cargo-${version}";
+  setupHook = ./setup-hook.sh;
 }

pkgs/development/tools/build-managers/cargo/default.nix

@@ -0,0 +1,32 @@
+{ stdenv, fetchgit, rustPlatform, file, curl, python, pkgconfig, openssl
+, cmake, zlib }:
+
+with ((import ./common.nix) { inherit stdenv; version = "2015-04-14"; });
+
+with rustPlatform;
+
+buildRustPackage rec {
+  inherit name version meta setupHook;
+
+  src = fetchgit {
+    url = "https://github.com/rust-lang/cargo.git";
+    rev = "d49b44358ed800351647571144257d35ac0886cf";
+    sha256 = "1kaims28237mvp1qpw2cfgb3684jr54ivkdag0lw8iv9xap4i35y";
+    leaveDotGit = true;
+  };
+
+  depsSha256 = "1yi39asmnrya8w83jrjxym658cf1a5ffp8ym8502rqqvx30y0yx4";
+
+  buildInputs = [ file curl pkgconfig python openssl cmake zlib ];
+
+  configurePhase = ''
+    ./configure --prefix=$out --local-cargo=${cargo}/bin/cargo
+  '';
+
+  buildPhase = "make";
+
+  installPhase = ''
+    make install
+    ${postInstall}
+  '';
+}

pkgs/development/tools/build-managers/cargo/setup-hook.sh

@@ -0,0 +1,6 @@
+if [[ -n "$cargoDeps" ]]; then
+   echo "Using cargo deps from $cargoDeps"
+   cp -r $cargoDeps deps
+   chmod +w deps -R
+   export CARGO_HOME=$(realpath deps)
+fi

pkgs/development/tools/build-managers/cargo/snapshot.nix

@@ -19,11 +19,8 @@ let snapshotHash = if stdenv.system == "i686-linux"
     snapshotName = "cargo-nightly-${platform}.tar.gz";
 in
 
-
 stdenv.mkDerivation {
-  inherit name;
-  inherit version;
-  inherit meta;
+  inherit name version meta setupHook;
 
   src = fetchurl {
     url = "https://static-rust-lang-org.s3.amazonaws.com/cargo-dist/${snapshotDate}/${snapshotName}";
@@ -35,10 +32,8 @@ stdenv.mkDerivation {
   installPhase = ''
     mkdir -p "$out"
     ./install.sh "--prefix=$out"
-    rm "$out/lib/rustlib/components" \
-       "$out/lib/rustlib/install.log" \
-       "$out/lib/rustlib/rust-installer-version" \
-       "$out/lib/rustlib/uninstall.sh"
+
+    ${postInstall}
   '' + (if stdenv.isLinux then ''
     patchelf --interpreter "${stdenv.glibc}/lib/${stdenv.cc.dynamicLinker}" \
              --set-rpath "${stdenv.cc.cc}/lib/:${stdenv.cc.cc}/lib64/:${zlib}/lib" \

pkgs/development/tools/rust/racer/default.nix

@@ -1,6 +1,8 @@
-{stdenv, fetchgit, rustc, cargo, makeWrapper }:
+{stdenv, fetchgit, rustPlatform, makeWrapper }:
 
-stdenv.mkDerivation rec {
+with rustPlatform;
+
+buildRustPackage rec {
   #TODO add emacs support
   name = "racer-git-2015-04-12";
   src = fetchgit {
@@ -9,11 +11,9 @@ stdenv.mkDerivation rec {
     sha256 = "0a768gvjry86l0xa5q0122iyq7zn2h9adfniglsgrbs4fan49xyn";
   };
 
-  buildInputs = [ rustc cargo makeWrapper ];
+  depsSha256 = "0x1rq012k04ci18w5fll56jn011f1yyprs38pb3r223bag94ivsy";
 
-  buildPhase = ''
-    CARGO_HOME="$NIX_BUILD_TOP/.cargo" cargo build --release
-  '';
+  buildInputs = [ makeWrapper ];
 
   installPhase = ''
     mkdir -p $out/bin