diff --git a/pkgs/development/compilers/rustc/generic.nix b/pkgs/development/compilers/rustc/generic.nix
index 6bb60c6dc69..ee7d0c7749d 100644
--- a/pkgs/development/compilers/rustc/generic.nix
+++ b/pkgs/development/compilers/rustc/generic.nix
@@ -118,15 +118,13 @@ stdenv.mkDerivation {
 
   configureFlags = configureFlags
                 ++ [ "--enable-local-rust" "--local-rust-root=$snapshot" "--enable-rpath" ]
+                # TODO always include starting from 1.3.0, superseeding patch and substituteInPlace below
+                ++ stdenv.lib.optional (!isRelease) [ "--default-linker=${stdenv.cc}/bin/cc" "--default-ar=${stdenv.cc.binutils}/bin/ar" ]
                 ++ stdenv.lib.optional (stdenv.cc.cc ? isClang) "--enable-clang";
 
   inherit patches;
 
   postPatch = ''
-    substituteInPlace src/librustc_back/target/mod.rs \
-      --subst-var-by "ccPath" "${stdenv.cc}/bin/cc" \
-      --subst-var-by "arPath" "${stdenv.cc.binutils}/bin/ar"
-
     substituteInPlace src/rust-installer/gen-install-script.sh \
       --replace /bin/echo "${coreutils}/bin/echo"
     substituteInPlace src/rust-installer/gen-installer.sh \
@@ -135,7 +133,11 @@ stdenv.mkDerivation {
     # Workaround for NixOS/nixpkgs#8676
     substituteInPlace mk/rustllvm.mk \
       --replace "\$\$(subst  /,//," "\$\$(subst /,/,"
-  '';
+    '' + stdenv.lib.optionalString (isRelease) ''
+    substituteInPlace src/librustc_back/target/mod.rs \
+      --subst-var-by "ccPath" "${stdenv.cc}/bin/cc" \
+      --subst-var-by "arPath" "${stdenv.cc.binutils}/bin/ar"
+    ''; # TODO remove in 1.3.0, superseeded by configure flags
 
   buildInputs = [ which file perl curl python27 makeWrapper git ]
     ++ stdenv.lib.optionals (!stdenv.isDarwin) [ procps valgrind ];
diff --git a/pkgs/development/compilers/rustc/head.nix b/pkgs/development/compilers/rustc/head.nix
index d65258a3a08..3c3239d2313 100644
--- a/pkgs/development/compilers/rustc/head.nix
+++ b/pkgs/development/compilers/rustc/head.nix
@@ -1,18 +1,16 @@
 { stdenv, callPackage }:
 callPackage ./generic.nix {
-  shortVersion = "2015-08-09";
+  shortVersion = "2015-09-05";
   isRelease = false;
-  # src rev for 2015-08-09's nightly channel
-  srcRev = "a5d33d891";
-  srcSha = "1iivzk9ggjh7y89rbw275apw4rfmzh4jk50kf0milljhvf72660n";
-  snapshotHashLinux686 = "3459275cdf3896f678e225843fa56f0d9fdbabe8";
-  snapshotHashLinux64 = "e451e3bd6e5fcef71e41ae6f3da9fb1cf0e13a0c";
-  snapshotHashDarwin686 = "428944a7984c0988e77909d82ca2ef77d96a1fbd";
-  snapshotHashDarwin64 = "b0515bb7d2892b9a58282fc865fee11a885406d6";
-  snapshotDate = "2015-07-26";
-  snapshotRev = "a5c12f4";
-  patches = [
-    ./patches/head.patch
-  ] ++ stdenv.lib.optional stdenv.needsPax ./patches/grsec.patch;
+  # src rev for 2015-09-05's nightly channel
+  srcRev = "779b2a9847319106647dcad12fc6dc472bc0cf4d";
+  srcSha = "0m22lxpcjnwa68bpxhfvp07k52gyds8ykif2pf5r2x22lw28vbg3";
+  snapshotHashLinux686 = "e2553bf399cd134a08ef3511a0a6ab0d7a667216";
+  snapshotHashLinux64 = "7df8ba9dec63ec77b857066109d4b6250f3d222f";
+  snapshotHashDarwin686 = "29750870c82a0347f8b8b735a4e2e0da26f5098d";
+  snapshotHashDarwin64 = "c9f2c588238b4c6998190c3abeb33fd6164099a2";
+  snapshotDate = "2015-08-11";
+  snapshotRev = "1af31d4";
+  patches = stdenv.lib.optional stdenv.needsPax ./patches/grsec.patch;
 }
 
diff --git a/pkgs/development/compilers/rustc/patches/head.patch b/pkgs/development/compilers/rustc/patches/head.patch
index ace22c825f9..2425fff04a1 100644
--- a/pkgs/development/compilers/rustc/patches/head.patch
+++ b/pkgs/development/compilers/rustc/patches/head.patch
@@ -1,18 +1,3 @@
-diff --git a/src/librustc_back/target/mod.rs b/src/librustc_back/target/mod.rs
-index 39e4291..b352bd1 100644
---- a/src/librustc_back/target/mod.rs
-+++ b/src/librustc_back/target/mod.rs
-@@ -179,8 +179,8 @@ impl Default for TargetOptions {
-     fn default() -> TargetOptions {
-         TargetOptions {
-             data_layout: String::new(),
--            linker: "cc".to_string(),
--            ar: "ar".to_string(),
-+            linker: "@ccPath@".to_string(), // ignore-tidy-linelength
-+            ar: "@arPath@".to_string(), // ignore-tidy-linelength
-             pre_link_args: Vec::new(),
-             post_link_args: Vec::new(),
-             cpu: "generic".to_string(),
 diff --git a/src/test/run-pass/issue-20797.rs b/src/test/run-pass/issue-20797.rs
 index 2772fc8..3d37b08 100644
 --- a/src/test/run-pass/issue-20797.rs
diff --git a/pkgs/top-level/rust-packages.nix b/pkgs/top-level/rust-packages.nix
index 0454288eb01..e79ff5ca57e 100644
--- a/pkgs/top-level/rust-packages.nix
+++ b/pkgs/top-level/rust-packages.nix
@@ -7,15 +7,15 @@
 { runCommand, fetchFromGitHub, git }:
 
 let
-  version = "2015-08-03";
-  rev = "dd3e0cecc30d0efbb50dfe76c83900568502af45";
+  version = "2015-08-21";
+  rev = "02e31a901d5f0942466ca7730431b547477126b1";
 
   src = fetchFromGitHub {
       inherit rev;
 
       owner = "rust-lang";
       repo = "crates.io-index";
-      sha256 = "0wlbaspa0mvljhkjjnglxwpp9b4mzcxpkdzrciljxwdsr8jvlz30";
+      sha256 = "0jppl2grir4wxc3da24h18h21kvh1wj0iff1b0z9vvx0a1iqp4gm";
   };
 
 in