diff --git a/foundation/src/stages/stage2/bash/default.nix b/foundation/src/stages/stage2/bash/default.nix
index 11e6e7f..4ea4295 100644
--- a/foundation/src/stages/stage2/bash/default.nix
+++ b/foundation/src/stages/stage2/bash/default.nix
@@ -76,6 +76,7 @@ in {
         deps.build.host = [
           stage1.gcc.package
           stage1.musl.package
+          stage1.coreutils.package
           stage1.binutils.package
           stage1.gnumake.package
           stage1.gnupatch.package
@@ -110,6 +111,7 @@ in {
           make -j $NIX_BUILD_CORES install-strip
           rm $out/bin/bashbug
 
+          ln -s $out/bin/bash $out/bin/sh
         '';
       };
     };
diff --git a/lib/src/dag/default.nix b/lib/src/dag/default.nix
index 432ded3..a904740 100644
--- a/lib/src/dag/default.nix
+++ b/lib/src/dag/default.nix
@@ -58,6 +58,10 @@ lib: {
         else sorted;
     };
 
+    apply = {
+      # defaults = graph: defaults:
+    };
+
     ## Map over the entries in a DAG and modify their values.
     ##
     ## @type (String -> a -> b) -> Dag a -> Dag b
diff --git a/tidepool/flake.lock b/tidepool/flake.lock
index 8ec01e0..4572262 100644
--- a/tidepool/flake.lock
+++ b/tidepool/flake.lock
@@ -8,10 +8,10 @@
       },
       "locked": {
         "dir": "foundation",
-        "dirtyRev": "2989fdc4fe153f13e7b6b476476805b03c419f0c-dirty",
-        "dirtyShortRev": "2989fdc-dirty",
-        "lastModified": 1718444137,
-        "narHash": "sha256-gArdjry0N4et4B+wQa31JyLJ448JWd9OFA1Roe3EOAc=",
+        "dirtyRev": "6bd35bf4d5f24b8e91d8afa589ea3088796b2baa-dirty",
+        "dirtyShortRev": "6bd35bf-dirty",
+        "lastModified": 1718450285,
+        "narHash": "sha256-/i3RlOudzZdl6UBdhMDRBAgVQTHOZDXEkSfRUw77aK8=",
         "type": "git",
         "url": "file:../?dir=foundation"
       },
@@ -24,10 +24,10 @@
     "lib": {
       "locked": {
         "dir": "lib",
-        "dirtyRev": "2989fdc4fe153f13e7b6b476476805b03c419f0c-dirty",
-        "dirtyShortRev": "2989fdc-dirty",
-        "lastModified": 1718444137,
-        "narHash": "sha256-gArdjry0N4et4B+wQa31JyLJ448JWd9OFA1Roe3EOAc=",
+        "dirtyRev": "6bd35bf4d5f24b8e91d8afa589ea3088796b2baa-dirty",
+        "dirtyShortRev": "6bd35bf-dirty",
+        "lastModified": 1718450285,
+        "narHash": "sha256-/i3RlOudzZdl6UBdhMDRBAgVQTHOZDXEkSfRUw77aK8=",
         "type": "git",
         "url": "file:../?dir=lib"
       },
diff --git a/tidepool/src/builders/basic.nix b/tidepool/src/builders/basic.nix
index ba2b042..ccde394 100644
--- a/tidepool/src/builders/basic.nix
+++ b/tidepool/src/builders/basic.nix
@@ -37,13 +37,16 @@ in {
 
             SHELL = cfg.executable;
 
-            PATH = lib.paths.bin (
-              (lib'.packages.dependencies.getPackages package.deps.build.host)
-              ++ [
-                foundation.stage2-bash
-                foundation.stage2-coreutils
-              ]
-            );
+            PATH = let
+              bins = lib.paths.bin (
+                (lib'.packages.dependencies.getPackages package.deps.build.host)
+                ++ [
+                  foundation.stage2-bash
+                  foundation.stage2-coreutils
+                ]
+              );
+            in
+              builtins.concatStringsSep ":" ([bins] ++ (lib.lists.when (package.env ? PATH) [package.env.PATH]));
 
             builder = cfg.executable;
 
diff --git a/tidepool/src/export.nix b/tidepool/src/export.nix
index 0b4c052..ba35e4a 100644
--- a/tidepool/src/export.nix
+++ b/tidepool/src/export.nix
@@ -12,8 +12,9 @@ in {
       modules = import ./modules.nix;
 
       packages = {
-        example-x = config.packages.example.x;
-        cross-example-x-x86_64-linux = config.packages.cross.x86_64-linux.example.x;
+        foundation-gcc = config.packages.foundation.gcc;
+        # example-x = config.packages.example.x;
+        # cross-example-x-x86_64-linux = config.packages.cross.x86_64-linux.example.x;
       };
     };
   };
diff --git a/tidepool/src/lib/packages.nix b/tidepool/src/lib/packages.nix
index a2a9959..b6bc0ce 100644
--- a/tidepool/src/lib/packages.nix
+++ b/tidepool/src/lib/packages.nix
@@ -17,14 +17,14 @@
 
       getLatest = alias: let
         versions = builtins.attrNames alias.versions;
-        sorted = builtins.sort (builtins.compareVersions) versions;
+        sorted = builtins.sort (lib.versions.gte) versions;
       in
         builtins.head sorted;
 
       build = package: system: cross: let
         resolved =
           if package ? versions
-          then package.versions.${config.preferences.packages.version} or (lib'.packages.getLatest package)
+          then package.versions.${config.preferences.packages.version} or (package.versions.${lib'.packages.getLatest package})
           else package;
 
         buildDependencies = builtins.mapAttrs (name: dep: lib'.packages.build dep system cross);
diff --git a/tidepool/src/lib/types.nix b/tidepool/src/lib/types.nix
index 8945019..414d5df 100644
--- a/tidepool/src/lib/types.nix
+++ b/tidepool/src/lib/types.nix
@@ -82,13 +82,6 @@
           extend = lib.options.create {
             description = "Extend the package's submodules with additional configuration.";
             type = lib.types.function lib.types.raw;
-            default.value = value:
-              meta.extend {
-                modules =
-                  if builtins.isAttrs value
-                  then [{config = value;}]
-                  else lib.lists.from.any value;
-              };
           };
 
           name = lib.options.create {
@@ -298,6 +291,16 @@
             default.value = config.builder.build config;
           };
         };
+
+        config = {
+          extend = value:
+            meta.extend {
+              modules =
+                if builtins.isAttrs value
+                then [{config = value;}]
+                else lib.lists.from.any value;
+            };
+        };
       });
     };
   };
diff --git a/tidepool/src/mirrors/default.nix b/tidepool/src/mirrors/default.nix
new file mode 100644
index 0000000..6de6799
--- /dev/null
+++ b/tidepool/src/mirrors/default.nix
@@ -0,0 +1,5 @@
+{
+  includes = [
+    ./gnu.nix
+  ];
+}
diff --git a/tidepool/src/mirrors/gnu.nix b/tidepool/src/mirrors/gnu.nix
new file mode 100644
index 0000000..a38a329
--- /dev/null
+++ b/tidepool/src/mirrors/gnu.nix
@@ -0,0 +1,9 @@
+{lib}: {
+  options.mirrors = {
+    gnu = lib.options.create {
+      description = "The GNU mirror to use";
+      type = lib.types.string;
+      default.value = "https://ftp.gnu.org/gnu";
+    };
+  };
+}
diff --git a/tidepool/src/modules.nix b/tidepool/src/modules.nix
index 0b97ad5..3c0e055 100644
--- a/tidepool/src/modules.nix
+++ b/tidepool/src/modules.nix
@@ -2,5 +2,6 @@
   builders = ./builders;
   exports = ./exports;
   lib = ./lib;
+  mirrors = ./mirrors;
   packages = ./packages;
 }
diff --git a/tidepool/src/packages/aux/foundation.nix b/tidepool/src/packages/aux/foundation.nix
deleted file mode 100644
index 2d769e7..0000000
--- a/tidepool/src/packages/aux/foundation.nix
+++ /dev/null
@@ -1,41 +0,0 @@
-{
-  lib,
-  lib',
-  config,
-  options,
-}: let
-  builders = config.builders;
-in {
-  config = {
-    packages = {
-      example = {
-        x = {
-          versions = {
-            "latest" = {config}: {
-              config = {
-                meta = {
-                  platforms = ["i686-linux" "x86_64-linux"];
-                };
-
-                pname = "x";
-                version = "1.0.0";
-
-                builder = builders.basic;
-
-                phases = {
-                  build = ''
-                    make --build ${config.platform.build.double} --host ${config.platform.host.double}
-                  '';
-
-                  install = lib.dag.entry.after ["build"] ''
-                    make install DESTDIR=$out
-                  '';
-                };
-              };
-            };
-          };
-        };
-      };
-    };
-  };
-}
diff --git a/tidepool/src/packages/default.nix b/tidepool/src/packages/default.nix
index 555922c..3ef6b4a 100644
--- a/tidepool/src/packages/default.nix
+++ b/tidepool/src/packages/default.nix
@@ -8,7 +8,7 @@
   packages = builtins.removeAttrs config.packages ["cross"];
 in {
   includes = [
-    ./aux/foundation.nix
+    ./foundation
   ];
 
   options = {
@@ -37,7 +37,7 @@ in {
     };
   };
 
-  config.packages.cross = lib.attrs.generate doubles (
+  config.packages.config.cross = lib.attrs.generate doubles (
     system:
       builtins.mapAttrs
       (
diff --git a/tidepool/src/packages/foundation/default.nix b/tidepool/src/packages/foundation/default.nix
new file mode 100644
index 0000000..5772791
--- /dev/null
+++ b/tidepool/src/packages/foundation/default.nix
@@ -0,0 +1,43 @@
+{
+  lib,
+  lib',
+  config,
+  options,
+}: {
+  includes = [
+    ./gcc
+  ];
+
+  config = {
+    packages = {
+      # example = {
+      #   x = {
+      #     versions = {
+      #       "latest" = {config}: {
+      #         config = {
+      #           meta = {
+      #             platforms = ["i686-linux" "x86_64-linux"];
+      #           };
+
+      #           pname = "x";
+      #           version = "1.0.0";
+
+      #           builder = builders.basic;
+
+      #           phases = {
+      #             build = ''
+      #               make --build ${config.platform.build.double} --host ${config.platform.host.double}
+      #             '';
+
+      #             install = lib.dag.entry.after ["build"] ''
+      #               make install DESTDIR=$out
+      #             '';
+      #           };
+      #         };
+      #       };
+      #     };
+      #   };
+      # };
+    };
+  };
+}
diff --git a/tidepool/src/packages/foundation/gcc/default.nix b/tidepool/src/packages/foundation/gcc/default.nix
new file mode 100644
index 0000000..5657d52
--- /dev/null
+++ b/tidepool/src/packages/foundation/gcc/default.nix
@@ -0,0 +1,203 @@
+{
+  lib,
+  lib',
+  config,
+  options,
+}: let
+  inherit
+    (config)
+    mirrors
+    builders
+    # These are the upstream foundational packages exported from the Aux Foundation project.
+    
+    foundation
+    ;
+in {
+  config.packages.foundation.gcc = {
+    versions = {
+      "13.2.0" = {config}: {
+        options = {
+          src = lib.options.create {
+            type = lib.types.derivation;
+            description = "Source for the package.";
+          };
+
+          cc = {
+            src = lib.options.create {
+              type = lib.types.derivation;
+              description = "The cc source for the package.";
+            };
+          };
+
+          gmp = {
+            src = lib.options.create {
+              type = lib.types.derivation;
+              description = "The gmp source for the package.";
+            };
+
+            version = lib.options.create {
+              type = lib.types.string;
+              description = "Version of gmp.";
+            };
+          };
+
+          mpfr = {
+            src = lib.options.create {
+              type = lib.types.derivation;
+              description = "The mpfr source for the package.";
+            };
+
+            version = lib.options.create {
+              type = lib.types.string;
+              description = "Version of mpfr.";
+            };
+          };
+
+          mpc = {
+            src = lib.options.create {
+              type = lib.types.derivation;
+              description = "The mpc source for the package.";
+            };
+
+            version = lib.options.create {
+              type = lib.types.string;
+              description = "Version of mpc.";
+            };
+          };
+
+          isl = {
+            src = lib.options.create {
+              type = lib.types.derivation;
+              description = "The isl source for the package.";
+            };
+            version = lib.options.create {
+              type = lib.types.string;
+              description = "Version of isl.";
+            };
+          };
+        };
+
+        config = {
+          meta = {
+            platforms = ["i686-linux"];
+          };
+
+          pname = "gcc";
+          version = "13.2.0";
+
+          builder = builders.basic;
+
+          env = {
+            PATH = lib.paths.bin [
+              foundation.stage2-gcc
+              foundation.stage2-binutils
+              foundation.stage2-gnumake
+              foundation.stage2-gnused
+              foundation.stage2-gnugrep
+              foundation.stage2-gawk
+              foundation.stage2-diffutils
+              foundation.stage2-findutils
+              foundation.stage2-gnutar
+              foundation.stage2-gzip
+              foundation.stage2-bzip2
+              foundation.stage1-xz
+            ];
+          };
+
+          phases = {
+            unpack = lib.dag.entry.before ["patch"] ''
+              # Unpack
+              tar xf ${config.src}
+              tar xf ${config.gmp.src}
+              tar xf ${config.mpfr.src}
+              tar xf ${config.mpc.src}
+              tar xf ${config.isl.src}
+              cd gcc-${config.version}
+
+              ln -s ../gmp-${config.gmp.version} gmp
+              ln -s ../mpfr-${config.mpfr.version} mpfr
+              ln -s ../mpc-${config.mpc.version} mpc
+              ln -s ../isl-${config.isl.version} isl
+            '';
+
+            patch = lib.dag.entry.between ["configure"] ["unpack"] ''
+              # Patch
+              # force musl even if host triple is gnu
+              sed -i 's|"os/gnu-linux"|"os/generic"|' libstdc++-v3/configure.host
+            '';
+
+            configure = lib.dag.entry.between ["build"] ["patch"] ''
+              # Configure
+              export CC="gcc -Wl,-dynamic-linker -Wl,${foundation.stage1-musl}/lib/libc.so"
+              export CXX="g++ -Wl,-dynamic-linker -Wl,${foundation.stage1-musl}/lib/libc.so"
+              export CFLAGS_FOR_TARGET="-Wl,-dynamic-linker -Wl,${foundation.stage1-musl}/lib/libc.so"
+              export LIBRARY_PATH="${foundation.stage1-musl}/lib"
+
+              bash ./configure \
+                --prefix=$out \
+                --build=${config.platform.build.triple} \
+                --host=${config.platform.host.triple} \
+                --with-native-system-header-dir=/include \
+                --with-sysroot=${foundation.stage1-musl} \
+                --enable-languages=c,c++ \
+                --disable-bootstrap \
+                --disable-libsanitizer \
+                --disable-lto \
+                --disable-multilib \
+                --disable-plugin \
+                CFLAGS=-static \
+                CXXFLAGS=-static
+            '';
+
+            build = lib.dag.entry.between ["install"] ["configure"] ''
+              # Build
+              make -j $NIX_BUILD_CORES
+            '';
+
+            install = lib.dag.entry.after ["build"] ''
+              # Install
+              make -j $NIX_BUILD_CORES install-strip
+            '';
+          };
+
+          src = builtins.fetchurl {
+            url = "${mirrors.gnu}/gcc/gcc-${config.version}/gcc-${config.version}.tar.xz";
+            sha256 = "4nXnZEKmBnNBon8Exca4PYYTFEAEwEE1KIY9xrXHQ9o=";
+          };
+
+          gmp = {
+            version = "6.3.0";
+            src = builtins.fetchurl {
+              url = "${mirrors.gnu}/gmp/gmp-${config.gmp.version}.tar.xz";
+              sha256 = "o8K4AgG4nmhhb0rTC8Zq7kknw85Q4zkpyoGdXENTiJg=";
+            };
+          };
+
+          mpfr = {
+            version = "4.2.1";
+            src = builtins.fetchurl {
+              url = "${mirrors.gnu}/mpfr/mpfr-${config.mpfr.version}.tar.xz";
+              sha256 = "J3gHNTpnJpeJlpRa8T5Sgp46vXqaW3+yeTiU4Y8fy7I=";
+            };
+          };
+
+          mpc = {
+            version = "1.3.1";
+            src = builtins.fetchurl {
+              url = "${mirrors.gnu}/mpc/mpc-${config.mpc.version}.tar.gz";
+              sha256 = "q2QkkvXPiCt0qgy3MM1BCoHtzb7IlRg86TDnBsHHWbg=";
+            };
+          };
+
+          isl = {
+            version = "0.24";
+            src = builtins.fetchurl {
+              url = "https://gcc.gnu.org/pub/gcc/infrastructure/isl-${config.isl.version}.tar.bz2";
+              sha256 = "/PeN2WVsEOuM+fvV9ZoLawE4YgX+GTSzsoegoYmBRcA=";
+            };
+          };
+        };
+      };
+    };
+  };
+}