Precompile seeded tools during the Nix build

flake.nix

@@ -143,6 +143,9 @@
           cargoArtifacts = hostArtifacts;
           doNotRemoveReferencesToVendorDir = true;
         });
+        precompiled = pkgs.runCommand "sausage-precompiled" {} ''
+          ${sausageUnwrapped}/bin/sausage precompile ${bundle} $out
+        '';
         # Keep the wrapper separate from crane's removal of toolchain references.
         sausage = pkgs.symlinkJoin {
           name = "sausage-${sausageUnwrapped.version}";
@@ -150,6 +153,7 @@
           nativeBuildInputs = [ pkgs.makeWrapper ];
           postBuild = ''
             wrapProgram $out/bin/sausage --set-default SAUSAGE_USERLAND ${bundle} \
+              --set-default SAUSAGE_PRECOMPILED ${precompiled} \
               --prefix PATH : ${runtimePath} \
               --set-default CC_wasm32_wasip2 ${wasiCcEnv.CC_wasm32_wasip2} \
               --set-default AR_wasm32_wasip2 ${wasiCcEnv.AR_wasm32_wasip2} \
@@ -170,6 +174,7 @@
           SAUSAGE_TEST_NO_BUILDER_SANDBOX = "1";
           SAUSAGE_NIX_CHECK = "1";
           SAUSAGE_USERLAND = bundle;
+          SAUSAGE_PRECOMPILED = precompiled;
           preCheck = ''
             export SAUSAGE_CACHE="$TMPDIR/sausage-cache"
             export CARGO_TARGET_DIR="$PWD/target"
@@ -181,8 +186,10 @@
         });
         checks.shell = pkgs.runCommand "sausage-shell" {} ''
           export SAUSAGE_CACHE="$TMPDIR/sausage-cache"
+          ${sausage}/bin/sausage init "$TMPDIR/world"
           ${sausage}/bin/sausage sh "$TMPDIR/world" -c \
             'set -e; echo hi | tr a-z A-Z; git --version; rg --version; awk "BEGIN {print 42}"; echo payload > /payload; tar -cf /test.tar /payload; tar -tf /test.tar; qjs -e "console.log(42)"; cargo --help; undo list' > output
+          test ! -e "$SAUSAGE_CACHE"
           cat output
           grep -qx HI output
           grep -q 'git version' output