5 files changed, 60 insertions, 20 deletions
diff --git a/pkgs/development/compilers/rust/1_38_0.nix b/pkgs/development/compilers/rust/1_38_0.nix
new file mode 100644
index 00000000000..5260ab20174
--- /dev/null
+++ b/pkgs/development/compilers/rust/1_38_0.nix
@@ -0,0 +1,20 @@
+import ./default.nix {
+  rustcVersion = "1.38.0";
+  rustcSha256 = "101dlpsfkq67p0hbwx4acqq6n90dj4bbprndizpgh1kigk566hk4";
+
+  # 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";
+    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_0;
+}
diff --git a/pkgs/development/compilers/rust/1_39_0.nix b/pkgs/development/compilers/rust/1_39_0.nix
new file mode 100644
index 00000000000..aa29c7a9ff7
--- /dev/null
+++ b/pkgs/development/compilers/rust/1_39_0.nix
@@ -0,0 +1,20 @@
+import ./default.nix {
+  rustcVersion = "1.39.0";
+  rustcSha256 = "0mwkc1bnil2cfyf6nglpvbn2y0zfbv44zfhsd5qg4c9rm6vgd8dl";
+
+  # Note: the version MUST be one version prior to the version we're
+  # building
+  bootstrapVersion = "1.38.0";
+
+  # fetch hashes by running `print-hashes.sh 1.38.0`
+  bootstrapHashes = {
+    i686-unknown-linux-gnu = "41aed8a350e24a0cac1444ed99b3dd24a90bc581dd88cb420c6e547d6b5f57af";
+    x86_64-unknown-linux-gnu = "adda26b3f0609dbfbdc2019da4a20101879b9db2134fae322a4e863a069ec221";
+    armv7-unknown-linux-gnueabihf = "8b1bf1680a61a643d6b5c7a3b1a1ce88448652756395e20ba5846739cbd085c4";
+    aarch64-unknown-linux-gnu = "06afd6d525326cea95c3aa658aaa8542eab26f44235565bb16913ac9d12b7bda";
+    i686-apple-darwin = "cdbf2807774bed350a3af6f41d7f7dd7ceff28777cde310c3ba90033188eb2f8";
+    x86_64-apple-darwin = "bd301b78ddcd5d4553962b115e1dca5436dd3755ed323f86f4485769286a8a5a";
+  };
+
+  selectRustPackage = pkgs: pkgs.rust_1_39_0;
+}
diff --git a/pkgs/development/compilers/rust/bootstrap.nix b/pkgs/development/compilers/rust/bootstrap.nix
index 7b774d066b7..54b2d3016e5 100644
--- a/pkgs/development/compilers/rust/bootstrap.nix
+++ b/pkgs/development/compilers/rust/bootstrap.nix
@@ -1,20 +1,6 @@
-{ stdenv, fetchurl, callPackage }:
+{ stdenv, fetchurl, callPackage, version, hashes }:
 
 let
-  # Note: the version MUST be one version prior to the version we're
-  # building
-  version = "1.37.0";
-
-  # fetch hashes by running `print-hashes.sh 1.37.0`
-  hashes = {
-    i686-unknown-linux-gnu = "74510e0e52a55e65a9f716673c2cda4d2bd427e2453541c6993c77c3ec04acf9";
-    x86_64-unknown-linux-gnu = "cb573229bfd32928177c3835fdeb62d52da64806b844bc1095c6225b0665a1cb";
-    armv7-unknown-linux-gnueabihf = "5b87b877f0ed20c6a09ce26e7a15d8c61b26b62484b97e78a51099d0efefec98";
-    aarch64-unknown-linux-gnu = "263ef98fa3a6b2911b56f89c06615cdebf6ef676eb9b2493ad1539602f79b6ba";
-    i686-apple-darwin = "e45d0c4d882fc6c404ffa6fe790294f4ea96384a2b48804adbf723f3635477a8";
-    x86_64-apple-darwin = "b2310c97ffb964f253c4088c8d29865f876a49da2a45305493af5b5c7a3ca73d";
-  };
-
   platform =
     if stdenv.hostPlatform.system == "i686-linux"
     then "i686-unknown-linux-gnu"
diff --git a/pkgs/development/compilers/rust/default.nix b/pkgs/development/compilers/rust/default.nix
index a39cd785cf7..efd641efb6e 100644
--- a/pkgs/development/compilers/rust/default.nix
+++ b/pkgs/development/compilers/rust/default.nix
@@ -1,3 +1,9 @@
+{ rustcVersion
+, rustcSha256
+, bootstrapVersion
+, bootstrapHashes
+, selectRustPackage
+}:
 { stdenv, lib
 , buildPackages
 , newScope, callPackage
@@ -36,21 +42,27 @@
   # cycles / purify builds). In this way, nixpkgs would be in control of all
   # bootstrapping.
   packages = {
-    prebuilt = callPackage ./bootstrap.nix {};
+    prebuilt = callPackage ./bootstrap.nix {
+      version = bootstrapVersion;
+      hashes = bootstrapHashes;
+    };
     stable = lib.makeScope newScope (self: let
       # Like `buildRustPackages`, but may also contain prebuilt binaries to
       # break cycle. Just like `bootstrapTools` for nixpkgs as a whole,
       # nothing in the final package set should refer to this.
       bootstrapRustPackages = self.buildRustPackages.overrideScope' (_: _:
         lib.optionalAttrs (stdenv.buildPlatform == stdenv.hostPlatform)
-          buildPackages.rust.packages.prebuilt);
+          (selectRustPackage buildPackages).packages.prebuilt);
       bootRustPlatform = makeRustPlatform bootstrapRustPackages;
     in {
       # Packages suitable for build-time, e.g. `build.rs`-type stuff.
-      buildRustPackages = buildPackages.rust.packages.stable;
+      buildRustPackages = (selectRustPackage buildPackages).packages.stable;
       # Analogous to stdenv
       rustPlatform = makeRustPlatform self.buildRustPackages;
       rustc = self.callPackage ./rustc.nix ({
+        version = rustcVersion;
+        sha256 = rustcSha256;
+
         # Use boot package set to break cycle
         rustPlatform = bootRustPlatform;
       } // lib.optionalAttrs (stdenv.cc.isClang && stdenv.hostPlatform == stdenv.buildPlatform) {
diff --git a/pkgs/development/compilers/rust/rustc.nix b/pkgs/development/compilers/rust/rustc.nix
index 430d22f7653..8a7d680010d 100644
--- a/pkgs/development/compilers/rust/rustc.nix
+++ b/pkgs/development/compilers/rust/rustc.nix
@@ -4,6 +4,8 @@
 , pkgconfig, openssl
 , which, libffi
 , withBundledLLVM ? false
+, version
+, sha256
 }:
 
 let
@@ -18,11 +20,11 @@ let
   llvmShared = llvm_7.override { enableSharedLibraries = true; };
 in stdenv.mkDerivation rec {
   pname = "rustc";
-  version = "1.38.0";
+  inherit version;
 
   src = fetchurl {
     url = "https://static.rust-lang.org/dist/rustc-${version}-src.tar.gz";
-    sha256 = "101dlpsfkq67p0hbwx4acqq6n90dj4bbprndizpgh1kigk566hk4";
+    inherit sha256;
   };
 
   __darwinAllowLocalNetworking = true;