Merge branch 'master' into staging

pkgs/development/compilers/rust/1_38.nix

@@ -1,22 +0,0 @@
-import ./default.nix {
-  rustcVersion = "1.38.0";
-  rustcSha256 = "101dlpsfkq67p0hbwx4acqq6n90dj4bbprndizpgh1kigk566hk4";
-  enableRustcDev = false;
-
-  # Note: the version MUST be one version prior to the version we're
-  # building
-  bootstrapVersion = "1.37.0";
-
-  # fetch hashes by running `print-hashes.sh 1.37.0`
-  bootstrapHashes = {
-    i686-unknown-linux-gnu = "74510e0e52a55e65a9f716673c2cda4d2bd427e2453541c6993c77c3ec04acf9";
-    x86_64-unknown-linux-gnu = "cb573229bfd32928177c3835fdeb62d52da64806b844bc1095c6225b0665a1cb";
-    arm-unknown-linux-gnueabihf = "272739fbb23cf6c2040c1813af9c8c7f386cac37d9de638f22a1816eb96bc0ae";
-    armv7-unknown-linux-gnueabihf = "5b87b877f0ed20c6a09ce26e7a15d8c61b26b62484b97e78a51099d0efefec98";
-    aarch64-unknown-linux-gnu = "263ef98fa3a6b2911b56f89c06615cdebf6ef676eb9b2493ad1539602f79b6ba";
-    i686-apple-darwin = "e45d0c4d882fc6c404ffa6fe790294f4ea96384a2b48804adbf723f3635477a8";
-    x86_64-apple-darwin = "b2310c97ffb964f253c4088c8d29865f876a49da2a45305493af5b5c7a3ca73d";
-  };
-
-  selectRustPackage = pkgs: pkgs.rust_1_38;
-}

pkgs/development/compilers/rust/default.nix

@@ -18,8 +18,9 @@
       "armv7a" = "armv7";
       "armv7l" = "armv7";
       "armv6l" = "arm";
-    }.${cpu.name} or cpu.name;
-  in "${cpu_}-${vendor.name}-${kernel.name}${lib.optionalString (abi.name != "unknown") "-${abi.name}"}";
+    }.${cpu.name} or platform.rustc.arch or cpu.name;
+  in platform.rustc.config
+    or "${cpu_}-${vendor.name}-${kernel.name}${lib.optionalString (abi.name != "unknown") "-${abi.name}"}";
 
   makeRustPlatform = { rustc, cargo, ... }: rec {
     rust = {
@@ -30,14 +31,8 @@
       inherit cargo;
     };
 
-    # N.B. This is a legacy fetcher implementation that is being phased out and deleted.
-    # See ../../../build-support/rust/README.md for details.
-    fetchcargo = buildPackages.callPackage ../../../build-support/rust/fetchcargo.nix {
-      inherit cargo;
-    };
-
     buildRustPackage = callPackage ../../../build-support/rust {
-      inherit rustc cargo fetchcargo fetchCargoTarball;
+      inherit rustc cargo fetchCargoTarball;
     };
 
     rustcSrc = callPackage ./rust-src.nix {