diff --git a/hacking/nix/scope/default.nix b/hacking/nix/scope/default.nix
index 339efdbaa..1f79afae0 100644
--- a/hacking/nix/scope/default.nix
+++ b/hacking/nix/scope/default.nix
@@ -62,7 +62,7 @@ superCallPackage ../rust-utils {} self //
     sha256 = "sha256-GJR7CjFPMh450uP/EUzXeng15vusV3ktq7Cioop945U=";
   };
 
-  defaultRustEnvironment = elaborateRustEnvironment (mkDefaultElaborateRustEnvironmentArgs {
+  upstreamDefaultRustEnvironment = elaborateRustEnvironment (mkDefaultElaborateRustEnvironmentArgs {
     rustToolchain = defaultRustToolchain;
   } // {
     channel = (builtins.fromTOML (builtins.readFile topLevelRustToolchainFile)).toolchain.channel;
@@ -79,6 +79,11 @@ superCallPackage ../rust-utils {} self //
         ];
   });
 
+  ferroceneDefaultRustEnvironment = ferrocene.rustEnvironment;
+
+  defaultRustEnvironment = upstreamDefaultRustEnvironment;
+  # defaultRustEnvironment = ferroceneDefaultRustEnvironment;
+
   mkDefaultElaborateRustEnvironmentArgs = { rustToolchain }: rec {
     inherit rustToolchain;
 
@@ -151,7 +156,7 @@ superCallPackage ../rust-utils {} self //
         };
       };
 
-      dir = runCommand "targest" {
+      dir = runCommand "target" {
         nativeBuildInputs = [ tool ];
       } ''
         mkdir $out
@@ -192,6 +197,8 @@ superCallPackage ../rust-utils {} self //
 
   dafny = callBuildBuildPackage ./dafny {};
 
+  ferrocene = callBuildBuildPackage ./ferrocene {};
+
   ### local tools
 
   mkTool = rootCrate: buildCratesInLayers {
diff --git a/hacking/nix/scope/ferrocene/.gitignore b/hacking/nix/scope/ferrocene/.gitignore
new file mode 100644
index 000000000..eab687475
--- /dev/null
+++ b/hacking/nix/scope/ferrocene/.gitignore
@@ -0,0 +1,7 @@
+#
+# Copyright 2024, Colias Group, LLC
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+/SHA256SUMS
diff --git a/hacking/nix/scope/ferrocene/default.nix b/hacking/nix/scope/ferrocene/default.nix
new file mode 100644
index 000000000..338086bd4
--- /dev/null
+++ b/hacking/nix/scope/ferrocene/default.nix
@@ -0,0 +1,225 @@
+#
+# Copyright 2024, Colias Group, LLC
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+{ lib
+, hostPlatform
+, stdenv
+, requireFile
+, fetchFromGitHub
+, zlib
+
+, fenix
+, crateUtils
+, elaborateRustEnvironment
+, mkDefaultElaborateRustEnvironmentArgs
+, mkMkCustomTargetPathForEnvironment
+}:
+
+let
+  parseHashesFile = fileContents:
+    let
+      rawLines = lib.splitString "\n" fileContents;
+      lines = assert lib.last rawLines == ""; lib.init rawLines;
+      parseLine = line:
+        let
+          parts = builtins.match ''([0-9a-f]{64})  (.*)'' line;
+          hash = lib.elemAt parts 0;
+          fname = lib.elemAt parts 1;
+        in
+          lib.nameValuePair fname hash;
+    in
+      lib.listToAttrs (map parseLine lines);
+
+  mkFiles = versionName: lib.mapAttrs (fname: sha256: requireFile {
+    name = fname;
+    url = "https://releases.ferrocene.dev/ferrocene/files/${versionName}/index.html";
+    inherit sha256;
+  });
+
+  rpath = "${zlib}/lib:$out/lib";
+
+  mkComponent = { componentName, nameSuffix, src, rustc, libcManifestDir }: stdenv.mkDerivation {
+    name = "${componentName}${nameSuffix}";
+    inherit src;
+    sourceRoot = ".";
+    installPhase = ''
+      cp -r . $out
+
+      rm $out/lib/rustlib/{components,install.log,manifest-*,rust-installer-version,uninstall.sh} || true
+
+      ${lib.optionalString stdenv.isLinux ''
+        if [ -d $out/bin ]; then
+          for file in $(find $out/bin -type f); do
+            if isELF "$file"; then
+              patchelf \
+                --set-interpreter ${stdenv.cc.bintools.dynamicLinker} \
+                --set-rpath ${rpath} \
+                "$file" || true
+            fi
+          done
+        fi
+
+        if [ -d $out/lib ]; then
+          for file in $(find $out/lib -type f); do
+            if isELF "$file"; then
+              patchelf --set-rpath ${rpath} "$file" || true
+            fi
+          done
+        fi
+
+        if [ -d $out/libexec ]; then
+          for file in $(find $out/libexec -type f); do
+            if isELF "$file"; then
+              patchelf \
+                --set-interpreter ${stdenv.cc.bintools.dynamicLinker} \
+                --set-rpath ${rpath} \
+                "$file" || true
+            fi
+          done
+        fi
+
+        ${lib.optionalString (componentName == "rustc") ''
+          for file in $(find $out/lib/rustlib/*/bin -type f); do
+            if isELF "$file"; then
+              patchelf \
+                --set-interpreter ${stdenv.cc.bintools.dynamicLinker} \
+                --set-rpath ${stdenv.cc.cc.lib}/lib:${rpath} \
+                "$file" || true
+            fi
+          done
+        ''}
+
+        ${lib.optionalString (componentName == "llvm-tools") ''
+          for file in $out/lib/rustlib/*/bin/*; do
+            patchelf \
+              --set-interpreter ${stdenv.cc.bintools.dynamicLinker} \
+              --set-rpath $out/lib/rustlib/*/lib \
+              "$file" || true
+          done
+        ''}
+      ''}
+
+      ${lib.optionalString (componentName == "rustfmt") ''
+        ${lib.optionalString stdenv.isLinux ''
+          patchelf \
+            --set-rpath ${rustc}/lib $out/bin/rustfmt || true
+        ''}
+        ${lib.optionalString stdenv.isDarwin ''
+          install_name_tool \
+            -add_rpath ${rustc}/lib $out/bin/rustfmt || true
+        ''}
+      ''}
+
+      ${lib.optionalString (componentName == "rust-analyzer") ''
+        ${lib.optionalString stdenv.isLinux ''
+          patchelf \
+            --set-rpath ${rustc}/lib $out/bin/rust-analyzer || true
+        ''}
+        ${lib.optionalString stdenv.isDarwin ''
+          install_name_tool \
+            -add_rpath ${rustc}/lib $out/bin/rust-analyzer || true
+        ''}
+      ''}
+
+      ${lib.optionalString (componentName == "rust-src") ''
+        substituteInPlace $out/lib/rustlib/src/rust/library/Cargo.toml \
+          --replace ../ferrocene/library/libc ${libcManifestDir}
+      ''}
+    '';
+    dontStrip = true;
+  };
+
+  defaultComponentNames = [
+    "rustc"
+    "rust-src"
+    "rust-std"
+    "cargo"
+    "clippy"
+    "llvm-tools"
+    "rustfmt"
+  ];
+
+  mkToolchain = { hashesFilePath, arch, versionTag, versionName, libcManifestDir, componentNames ? defaultComponentNames }:
+    let
+      files = mkFiles versionName (parseHashesFile (builtins.readFile hashesFilePath));
+      byName = lib.fix (self: lib.listToAttrs (lib.forEach componentNames (componentName:
+        let
+          nameSuffix = "${
+            lib.optionalString (componentName != "rust-src") "-${arch}"
+          }-${versionTag}";
+          fname = "${componentName}${nameSuffix}.tar.xz";
+          component = mkComponent {
+            inherit componentName;
+            inherit nameSuffix;
+            src = files.${fname};
+            inherit (self) rustc;
+            inherit libcManifestDir;
+          };
+        in
+          lib.nameValuePair componentName component
+      )));
+    in
+      fenix.combine (lib.attrValues byName);
+in
+
+let
+  # upstreamChannel = "1.79.0";
+  upstreamChannel = "beta";
+
+  # versionTag = "24.08.0";
+  versionTag = "6ce9c7ddc";
+  versionName = "pre-rolling-2024-09-11";
+
+  repo = fetchFromGitHub {
+    owner = "ferrocene";
+    repo = "ferrocene";
+    rev = "6ce9c7ddc767a9b4cddd4ef8a0d4a317bb63159a"; # branch release/1.82
+    hash = "sha256-r1s3ifDA9QF9dCPieChFjJo9cwEY6vi5RMtXWyUiw0g=";
+  };
+
+  libcManifestDir = "${repo}/ferrocene/library/libc";
+
+  # DO NOT CHECK IN THIS FILE
+  hashesFilePath = ./SHA256SUMS;
+
+  rustToolchain = mkToolchain {
+    inherit hashesFilePath;
+    arch = hostPlatform.config;
+    inherit versionTag versionName;
+    inherit libcManifestDir;
+  };
+in
+
+let
+  upstreamRustToolchain = fenix.fromToolchainFile {
+    file = crateUtils.toTOMLFile "rust-toolchain.toml" {
+      toolchain = {
+        channel = upstreamChannel;
+        components = [ "rustc-dev" ];
+      };
+    };
+    sha256 = "sha256-4vvAuAhW4cBwR+g1IrI79X7gKL4VsEYKD05XZL0rLc4=";
+  };
+
+  upstreamRustEnvironment = lib.fix (self: elaborateRustEnvironment (mkDefaultElaborateRustEnvironmentArgs {
+    rustToolchain = upstreamRustToolchain;
+  } // {
+    channel = upstreamChannel;
+  }));
+
+  rustEnvironment = lib.fix (self: elaborateRustEnvironment (mkDefaultElaborateRustEnvironmentArgs {
+    inherit rustToolchain;
+  } // {
+    channel = upstreamChannel;
+    mkCustomTargetPath = mkMkCustomTargetPathForEnvironment {
+      rustEnvironment = upstreamRustEnvironment;
+    };
+  }));
+
+in {
+  inherit rustEnvironment;
+  inherit upstreamRustEnvironment;
+}
diff --git a/hacking/nix/scope/microkit/default.nix b/hacking/nix/scope/microkit/default.nix
index 3c41acfad..cc8a45c4d 100644
--- a/hacking/nix/scope/microkit/default.nix
+++ b/hacking/nix/scope/microkit/default.nix
@@ -93,7 +93,7 @@ let
       cargoConfigFile = toTOMLFile "config.toml" vendoredLockfile.configFragment;
 
     in
-      stdenv.mkDerivation {
+      stdenv.mkDerivation ({
         name = "microkit-sdk-just-tool";
 
         src = lib.cleanSource (microkitSource + "/tool/microkit");
@@ -106,6 +106,11 @@ let
           buildPackages.stdenv.cc
         ];
 
+      } // lib.optionalAttrs (!rustEnvironment.isNightly) {
+        # HACK
+        RUSTC_BOOTSTRAP = 1;
+      } // {
+
         dontInstall = true;
         dontFixup = true;
 
@@ -118,7 +123,7 @@ let
         buildPhase = ''
           cargo build -Z unstable-options --frozen --config ${cargoConfigFile} ${rustEnvironment.artifactDirFlag} $out/bin
         '';
-      };
+      });
 
   mkLoader =
     { systemXML
diff --git a/hacking/nix/scope/world/docs.nix b/hacking/nix/scope/world/docs.nix
index 3a304310b..c29c2ded5 100644
--- a/hacking/nix/scope/world/docs.nix
+++ b/hacking/nix/scope/world/docs.nix
@@ -130,7 +130,10 @@ let
         nativeBuildInputs = [ rsync rustToolchain ];
         RUST_TARGET_PATH = rustEnvironment.mkTargetPath targetTriple;
         LIBCLANG_PATH = libclangPath;
-      } // seL4RustEnvVars)  ''
+      } // lib.optionalAttrs (!rustEnvironment.isNightly) {
+        # HACK
+        RUSTC_BOOTSTRAP = 1;
+      } // seL4RustEnvVars) ''
         target_dir=$(pwd)/target
 
         cargo doc \