diff --git a/tidepool/src/builders/foundation/basic.nix b/tidepool/src/builders/foundation/basic.nix
index e59a537..6738aff 100644
--- a/tidepool/src/builders/foundation/basic.nix
+++ b/tidepool/src/builders/foundation/basic.nix
@@ -71,64 +71,81 @@ in
               (lib.packages.build packages.foundation.bash.versions."5.2.15-stage1" "x86_64-linux" system).package
             }/bin/bash";
 
-        built = builtins.derivation (
-          package.env
-          // {
-            inherit (package) name;
-            inherit script system;
+        built = builtins.derivation ({
+          inherit (package) name env;
+          inherit script system;
 
-            outputs = builtins.attrNames (lib.packages.getOutputs package);
+          __structuredAttrs = true;
 
-            passAsFile = [ "script" ];
+          outputs = builtins.attrNames (lib.packages.getOutputs package);
 
-            SHELL = executable;
+          SHELL = executable;
 
-            PATH =
-              let
-                bins = lib.paths.bin (
-                  (lib.packages.dependencies.get dependencies.build)
-                  ++ (lib.packages.dependencies.get dependencies.host)
-                  ++ lib.lists.when (system == "i686-linux") [
-                    foundation.stage2-bash
-                    foundation.stage2-coreutils
-                  ]
-                  ++ lib.lists.when (system == "x86_64-linux") [
-                    (lib.packages.build packages.foundation.bash.versions."5.2.15-stage1" "i686-linux" system).package
-                    (lib.packages.build packages.foundation.coreutils.versions."9.4-stage1" "i686-linux" system).package
-                  ]
-                  ++ lib.lists.when (system != "i686-linux" && system != "x86_64-linux") [
-                    (lib.packages.build packages.foundation.bash.versions."5.2.15-stage1" "x86_64-linux" system).package
-                    (lib.packages.build packages.foundation.coreutils.versions."9.4-stage1" "x86_64-linux" system)
-                    .package
-                  ]
-                );
-              in
-              builtins.concatStringsSep ":" (
-                [ bins ] ++ (lib.lists.when (package.env ? PATH) [ package.env.PATH ])
+          PATH =
+            let
+              bins = lib.paths.bin (
+                (lib.packages.dependencies.get dependencies.build)
+                ++ (lib.packages.dependencies.get dependencies.host)
+                ++ lib.lists.when (system == "i686-linux") [
+                  foundation.stage2-bash
+                  foundation.stage2-coreutils
+                ]
+                ++ lib.lists.when (system == "x86_64-linux") [
+                  (lib.packages.build packages.foundation.bash.versions."5.2.15-stage1" "i686-linux" system).package
+                  (lib.packages.build packages.foundation.coreutils.versions."9.4-stage1" "i686-linux" system).package
+                ]
+                ++ lib.lists.when (system != "i686-linux" && system != "x86_64-linux") [
+                  (lib.packages.build packages.foundation.bash.versions."5.2.15-stage1" "x86_64-linux" system).package
+                  (lib.packages.build packages.foundation.coreutils.versions."9.4-stage1" "x86_64-linux" system)
+                  .package
+                ]
               );
+            in
+            builtins.concatStringsSep ":" (
+              [ bins ] ++ (lib.lists.when (package.env ? PATH) [ package.env.PATH ])
+            );
 
-            builder = executable;
+          builder = executable;
 
-            args = [
-              "-e"
-              (builtins.toFile "bash-builder.sh" ''
-                export CONFIG_SHELL=$SHELL
+          args = [
+            "-e"
+            (builtins.toFile "bash-builder.sh" ''
+              set -eEuo pipefail
 
-                # Normalize the NIX_BUILD_CORES variable. The value might be 0, which
-                # means that we're supposed to try and auto-detect the number of
-                # available CPU cores at run-time.
-                NIX_BUILD_CORES="''${NIX_BUILD_CORES:-1}"
-                if ((NIX_BUILD_CORES <= 0)); then
-                  guess=$(nproc 2>/dev/null || true)
-                  ((NIX_BUILD_CORES = guess <= 0 ? 1 : guess))
-                fi
-                export NIX_BUILD_CORES
+              if [[ -e $NIX_ATTRS_SH_FILE ]]; then
+                source "$NIX_ATTRS_SH_FILE";
+              else
+                echo "Failed to find structuredAttrs"
+                exit 1
+              fi
 
-                bash -eux $scriptPath
-              '')
-            ];
-          }
-        );
+              export CONFIG_SHELL=$SHELL
+
+              # With structuredAttrs each output var must be exported manually
+              for outputName in "''${!outputs[@]}"; do
+                  # Need to set $out=/nix/store...
+                  export "$outputName=''${outputs[$outputName]}"
+              done
+
+              # Also need to export vars
+              for envVar in "''${!env[@]}"; do
+                  export "$envVar=''${env[$envVar]}"
+              done
+
+              # Normalize the NIX_BUILD_CORES variable. The value might be 0, which
+              # means that we're supposed to try and auto-detect the number of
+              # available CPU cores at run-time.
+              NIX_BUILD_CORES="''${NIX_BUILD_CORES:-1}"
+              if ((NIX_BUILD_CORES <= 0)); then
+                guess=$(nproc 2>/dev/null || true)
+                ((NIX_BUILD_CORES = guess <= 0 ? 1 : guess))
+              fi
+              export NIX_BUILD_CORES
+
+              eval "$script"
+            '')
+          ];
+        });
 
         result = built // {
           inherit package;