diff --git a/pkgs/development/compilers/rustc/head.nix b/pkgs/development/compilers/rustc/head.nix
index ab3458f435b..f81539fad9a 100644
--- a/pkgs/development/compilers/rustc/head.nix
+++ b/pkgs/development/compilers/rustc/head.nix
@@ -18,19 +18,19 @@ assert stdenv.gcc.gcc != null;
 
 */
 
-with ((import ./common.nix) {inherit stdenv; version = "0.12.0-pre-9a68da740"; });
+with ((import ./common.nix) {inherit stdenv; version = "0.12.0-pre-a2e7c4da9"; });
 
 let snapshot = if stdenv.system == "i686-linux"
-      then "5c2132b65f45c21b43d28de6a9460978b1a7b08a"
+      then "555aca74f9a268f80cab2df1147dc6406403e9e4"
       else if stdenv.system == "x86_64-linux"
-      then "152be582853c2cf1ddcc88b085153b52ebbeb065"
+      then "6a43c2f6c8ba2cbbcb9da1f7b58f748aef99f431"
       else if stdenv.system == "i686-darwin"
-      then "7adbb076aeae8e1d9bdf3fe968bc7ef8a8fe0096"
+      then "331bd7ef519cbb424188c546273e8c7d738f0894"
       else if stdenv.system == "x86_64-darwin"
-      then "152be582853c2cf1ddcc88b085153b52ebbeb065"
+      then "2c83a79a9febfe1d326acb17c3af76ba053c6ca9"
       else abort "no-snapshot for platform ${stdenv.system}";
-    snapshotDate = "2014-09-22";
-    snapshotRev = "437179e";
+    snapshotDate = "2014-10-04";
+    snapshotRev = "749ff5e";
     snapshotName = "rust-stage0-${snapshotDate}-${snapshotRev}-${platform}-${snapshot}.tar.bz2";
 
 in stdenv.mkDerivation {
@@ -40,8 +40,8 @@ in stdenv.mkDerivation {
 
   src = fetchgit {
     url = https://github.com/rust-lang/rust;
-    rev = "9a68da7401d9bef645a8b6a4e0ce4cae12604df4";
-    sha256 = "1nrmahz9scv06v8pyfgjl902dh9947irpqi78lh11r5lyixia8ci";
+    rev = "a2e7c4da9b331d337fba0b3911c6d3d7f48e8305";
+    sha256 = "1lpncqx3lfyjk6llfc7pd1iqxzfhj32hjqvj09zks73r4isc02n4";
   };
 
   # We need rust to build rust. If we don't provide it, configure will try to download it.
@@ -65,7 +65,7 @@ in stdenv.mkDerivation {
   configureFlags = [ "--enable-local-rust" "--local-rust-root=$snapshot" ];
 
   # The compiler requires cc, so we patch the source to tell it where to find it
-  patches = [ ./hardcode_paths.HEAD.patch ./local_stage0.HEAD.patch ./override_env.HEAD.patch ];
+  patches = [ ./hardcode_paths.HEAD.patch ./local_stage0.HEAD.patch ];
   postPatch = ''
     substituteInPlace src/librustc/back/link.rs \
       --subst-var-by "ccPath" "${stdenv.gcc}/bin/cc"
diff --git a/pkgs/development/compilers/rustc/override_env.HEAD.patch b/pkgs/development/compilers/rustc/override_env.HEAD.patch
deleted file mode 100644
index c050cde9633..00000000000
--- a/pkgs/development/compilers/rustc/override_env.HEAD.patch
+++ /dev/null
@@ -1,39 +0,0 @@
-commit 02f4c61bd6a2aedbf56169aff5b3a65c83c89557
-Author: Ricardo M. Correia <rcorreia@wizy.org>
-Date:   Tue Sep 30 15:57:06 2014 +0200
-
-    libstd: Pass-through PATH in test_override_env test
-    
-    In some operating systems (such as NixOS), `env` can only be found in
-    the explicitly-provided PATH, not in default places such as /bin or
-    /usr/bin. So we need to pass-through PATH when spawning the `env`
-    sub-process.
-
-diff --git a/src/libstd/io/process.rs b/src/libstd/io/process.rs
-index 83890d2..8fbf254 100644
---- a/src/libstd/io/process.rs
-+++ b/src/libstd/io/process.rs
-@@ -956,7 +956,22 @@ mod tests {
-     })
- 
-     iotest!(fn test_override_env() {
--        let new_env = vec![("RUN_TEST_NEW_ENV", "123")];
-+        use os;
-+        let mut new_env = vec![("RUN_TEST_NEW_ENV", "123")];
-+
-+        // In some operating systems (such as NixOS), `env` can only be found in
-+        // the explicitly-provided PATH env variable, not in default places
-+        // such as /bin or /usr/bin. So we need to pass through PATH to our
-+        // sub-process.
-+        let path_val: String;
-+        match os::getenv("PATH") {
-+            None => {}
-+            Some(val) => {
-+                path_val = val;
-+                new_env.push(("PATH", path_val.as_slice()))
-+            }
-+        }
-+
-         let prog = env_cmd().env_set_all(new_env.as_slice()).spawn().unwrap();
-         let result = prog.wait_with_output().unwrap();
-         let output = String::from_utf8_lossy(result.output.as_slice()).into_string();