build/speed(mirage): reseparate targets into their own derivation

Author: Julien Moutinho

pkgs/by-name/dnsvizor/mirage.nix

@@ -46,11 +46,11 @@ rec {
     };
 
   # Description: read opam files from mirage configuration
-  # and build a unikernel in a separate output
-  # for each one of the given targets.
+  # and build a unikernel for the given target.
   build = lib.extendMkDerivation {
     constructDrv = stdenv.mkDerivation;
     excludeDrvArgNames = [
+      "target"
       "materializedDir"
       "monorepoQuery"
       "overrideUnikernel"
@@ -62,8 +62,8 @@ rec {
       {
         pname,
         version,
-        targets,
         src,
+        target,
         monorepoQuery,
         materializedDir,
         mirageDir ? ".",
@@ -74,25 +74,14 @@ rec {
       }@args:
       let
         name = "mirage-${pname}";
-        mirageConfIFD = configure args;
-        mirageConf =
-          target:
-          configure (
-            args
-            // {
-              opamPackages = packages target;
-            }
-          ) target;
-        packagesMaterialized =
-          target: opam-nix.materializeOpamProject { } "${name}-${target}" (mirageConfIFD target) query;
-        monorepoMaterialized =
-          target: opam-nix.materializeBuildOpamMonorepo { } (mirageConfIFD target) monorepoQuery;
-        monorepo =
-          target: opam-nix.unmaterializeQueryToMonorepo { } (materializedDir + "/${target}/monorepo.json");
+        mirageConfIFD = configure args target;
+        mirageConf = configure (args // { opamPackages = packages; }) target;
+        packagesMaterialized = opam-nix.materializeOpamProject { } "${name}-${target}" mirageConfIFD query;
+        monorepoMaterialized = opam-nix.materializeBuildOpamMonorepo { } mirageConfIFD monorepoQuery;
+        monorepo = opam-nix.unmaterializeQueryToMonorepo { } (materializedDir + "/${target}/monorepo.json");
         packages =
-          target:
           (opam-nix.materializedDefsToScope {
-            sourceMap."${name}-${target}" = finalAttrs.passthru.mirageConf.${target};
+            sourceMap."${name}-${target}" = finalAttrs.passthru.mirageConf;
           } (materializedDir + "/${target}/packages.json")).overrideScope
             (
               finalOpam: previousOpam: {
@@ -113,7 +102,7 @@ rec {
                       echo '(vendored_dirs *)' > duniverse/dune
                       ${lib.concatStringsSep "\n" (
                         lib.mapAttrsToList (name: path: "cp -r ${path} duniverse/${lib.toLower name}") (
-                          finalAttrs.passthru.monorepo.${target}
+                          finalAttrs.passthru.monorepo
                         )
                       )}
                       dune build ${mirageDir} --profile release
@@ -139,25 +128,24 @@ rec {
       {
         inherit name;
         inherit src;
-        outputs = [ "out" ] ++ targets;
         installPhase = ''
           runHook preInstall
-          ${
-            if stdenv.hostPlatform.isLinux && lib.elem "unix" targets then
-              "ln -s $unix $out"
-            else if stdenv.hostPlatform.isDarwin && lib.elem "macosx" targets then
-              "ln -s $macosx $out"
-            else
-              "mkdir $out"
+          cp -R --no-preserve=mode ${finalAttrs.passthru.packages."${name}-${target}"} $out
+          ${lib.optionalString
+            (
+              (stdenv.hostPlatform.isLinux && target == "unix")
+              || (stdenv.hostPlatform.isDarwin && target == "macosx")
+            )
+            ''
+              install -Dm755 $out/share/mirageos/${pname} $out/bin/${pname}
+              rm -rf $out/share
+            ''
           }
-          ${lib.concatMapStringsSep "\n" (target: ''
-            cp -R ${finalAttrs.passthru.packages.${target}."${name}-${target}"} ''$${target}
-          '') targets}
           runHook postInstall
         '';
         passthru = {
           updateScript = writeShellApplication {
-            name = "dnsvizor-update";
+            name = "dnsvizor-update-${target}";
             runtimeInputs = [
               coreutils
               jq
@@ -166,28 +154,61 @@ rec {
             text = ''
               set -x
               materializedDir=$(nix --extra-experimental-features nix-command -L eval \
-                -f. ${pname}.passthru.materializedDir)
-            ''
-            + lib.concatMapStringsSep "\n" (target: ''
-              mkdir -p "${materializedDir}/${target}/"
+                -f. ${pname}.passthru.${target}.passthru.materializedDir)
+              mkdir -p "$materializedDir/${target}/"
               packagesJson=$(nix --extra-experimental-features nix-command -L build \
                 --no-link --print-out-paths --allow-import-from-derivation --show-trace \
-                -f. ${pname}.passthru.packagesMaterialized.${target})
-              jq <"$packagesJson" >"''${materializedDir}/${target}/packages.json"
+                -f. ${pname}.passthru.${target}.passthru.packagesMaterialized)
+              jq <"$packagesJson" >"$materializedDir/${target}/packages.json"
               monorepoJson=$(nix --extra-experimental-features nix-command -L build \
                 --no-link --print-out-paths --allow-import-from-derivation --show-trace \
-                -f. ${pname}.passthru.monorepoMaterialized.${target})
-              jq <"$monorepoJson" >"''${materializedDir}/${target}/monorepo.json"
+                -f. ${pname}.passthru.${target}.passthru.monorepoMaterialized)
+              jq <"$monorepoJson" >"$materializedDir/${target}/monorepo.json"
+            '';
+          };
+          inherit
+            materializedDir
+            mirageConf
+            mirageConfIFD
+            monorepo
+            monorepoMaterialized
+            packages
+            packagesMaterialized
+            ;
+        };
+      };
+  };
+
+  builds = lib.extendMkDerivation {
+    constructDrv = stdenv.mkDerivation;
+    excludeDrvArgNames = [
+      "target"
+      "materializedDir"
+      "monorepoQuery"
+      "overrideUnikernel"
+      "query"
+      "queryArgs"
+    ];
+    extendDrvArgs =
+      finalAttrs:
+      {
+        targets ? finalAttrs.targets or possibleTargets,
+        ...
+      }@args:
+      {
+        passthru = lib.genAttrs targets (target: build (args // { inherit target; })) // {
+          updateScript = writeShellApplication {
+            name = "dnsvizor-update";
+            text = lib.concatMapStringsSep "\n" (target: ''
+              ${lib.getExe finalAttrs.passthru.${target}.passthru.updateScript}
             '') targets;
           };
-          mirageConfIFD = lib.genAttrs targets mirageConfIFD;
-          mirageConf = lib.genAttrs targets mirageConf;
-          monorepoMaterialized = lib.genAttrs targets monorepoMaterialized;
-          packagesMaterialized = lib.genAttrs targets packagesMaterialized;
-          packages = lib.genAttrs targets packages;
-          monorepo = lib.genAttrs targets monorepo;
-          inherit materializedDir;
         };
+        installPhase = ''
+          runHook preInstall
+          mkdir -p $out
+          runHook postInstall
+        '';
       };
   };
 

pkgs/by-name/dnsvizor/package.nix

@@ -11,7 +11,7 @@
 let
   libMirage = callPackage ./mirage.nix { };
 in
-(libMirage.build (finalAttrs: {
+(libMirage.builds (finalAttrs: {
   pname = "dnsvizor";
   version = "0-unstable-2026-01-21";
   materializedDir = ./materialized;