Replace defaultBla.$system with bla.$system.default

This also simplifies some InstallableFlake logic and fixes 'nix
bundle' parsing its installable twice.

Fixes #5532.

src/libcmd/installables.cc

@@ -158,7 +158,10 @@ SourceExprCommand::SourceExprCommand()
 
 Strings SourceExprCommand::getDefaultFlakeAttrPaths()
 {
-    return {"defaultPackage." + settings.thisSystem.get()};
+    return {
+        "packages." + settings.thisSystem.get() + ".default",
+        "defaultPackage." + settings.thisSystem.get()
+    };
 }
 
 Strings SourceExprCommand::getDefaultFlakeAttrPathPrefixes()

src/nix/bundle.cc

@@ -49,9 +49,11 @@ struct CmdBundle : InstallableCommand
 
     Category category() override { return catSecondary; }
 
+    // FIXME: cut&paste from CmdRun.
     Strings getDefaultFlakeAttrPaths() override
     {
         Strings res{
+            "apps." + settings.thisSystem.get() + ".default",
             "defaultApp." + settings.thisSystem.get()
         };
         for (auto & s : SourceExprCommand::getDefaultFlakeAttrPaths())
@@ -61,10 +63,7 @@ struct CmdBundle : InstallableCommand
 
     Strings getDefaultFlakeAttrPathPrefixes() override
     {
-        Strings res{
+        Strings res{"apps." + settings.thisSystem.get() + "."};
-            "apps." + settings.thisSystem.get() + "."
-
-        };
         for (auto & s : SourceExprCommand::getDefaultFlakeAttrPathPrefixes())
             res.push_back(s);
         return res;
@@ -80,7 +79,9 @@ struct CmdBundle : InstallableCommand
         const flake::LockFlags lockFlags{ .writeLockFile = false };
         InstallableFlake bundler{this,
             evalState, std::move(bundlerFlakeRef), bundlerName,
-            {"defaultBundler." + settings.thisSystem.get()},
+            {"bundlers." + settings.thisSystem.get() + ".default",
+             "defaultBundler." + settings.thisSystem.get()
+            },
             {"bundlers." + settings.thisSystem.get() + "."},
             lockFlags
         };

src/nix/develop.cc

@@ -325,8 +325,15 @@ struct Common : InstallableCommand, MixProfile
 
     Strings getDefaultFlakeAttrPaths() override
     {
-        return {"devShell." + settings.thisSystem.get(), "defaultPackage." + settings.thisSystem.get()};
+        Strings paths{
+            "devShells." + settings.thisSystem.get() + ".default",
+            "devShell." + settings.thisSystem.get(),
+        };
+        for (auto & p : SourceExprCommand::getDefaultFlakeAttrPaths())
+            paths.push_back(p);
+        return paths;
     }
+
     Strings getDefaultFlakeAttrPathPrefixes() override
     {
         auto res = SourceExprCommand::getDefaultFlakeAttrPathPrefixes();

src/nix/flake.cc

@@ -651,7 +651,7 @@ struct CmdFlakeCheck : FlakeCommand
 };
 
 static Strings defaultTemplateAttrPathsPrefixes{"templates."};
-static Strings defaultTemplateAttrPaths = {"defaultTemplate"};
+static Strings defaultTemplateAttrPaths = {"templates.default", "defaultTemplate"};
 
 struct CmdFlakeInitCommon : virtual Args, EvalCommand
 {

src/nix/run.cc

@@ -158,7 +158,10 @@ struct CmdRun : InstallableCommand
 
     Strings getDefaultFlakeAttrPaths() override
     {
-        Strings res{"defaultApp." + settings.thisSystem.get()};
+        Strings res{
+            "apps." + settings.thisSystem.get() + ".default",
+            "defaultApp." + settings.thisSystem.get(),
+        };
         for (auto & s : SourceExprCommand::getDefaultFlakeAttrPaths())
             res.push_back(s);
         return res;

tests/flake-bundler.sh

@@ -10,26 +10,28 @@ cd $TEST_HOME
 cat <<EOF > flake.nix
 {
     outputs = {self}: {
-       bundlers.$system.simple = drv:
+      bundlers.$system = rec {
+        simple = drv:
           if drv?type && drv.type == "derivation"
           then drv
-          else self.defaultPackage.$system;
+          else self.packages.$system.default;
-       defaultBundler.$system = self.bundlers.$system.simple;
+        default = simple;
-       defaultPackage.$system = import ./simple.nix;
+      };
-       defaultApp.$system = {
+      packages.$system.default = import ./simple.nix;
-         type = "app";
+      apps.$system.default = {
-         program = "\${import ./simple.nix}/hello";
+        type = "app";
-       };
+        program = "\${import ./simple.nix}/hello";
+      };
     };
 }
 EOF
 nix build .#
 nix bundle --bundler .# .#
-nix bundle --bundler .#defaultBundler.$system  .#defaultPackage.$system
+nix bundle --bundler .#bundlers.$system.default .#packages.$system.default
-nix bundle --bundler .#bundlers.$system.simple .#defaultPackage.$system
+nix bundle --bundler .#bundlers.$system.simple  .#packages.$system.default
 
-nix bundle --bundler .#defaultBundler.$system  .#defaultApp.$system
+nix bundle --bundler .#bundlers.$system.default .#apps.$system.default
-nix bundle --bundler .#bundlers.$system.simple .#defaultApp.$system
+nix bundle --bundler .#bundlers.$system.simple  .#apps.$system.default
 
 clearStore
 

tests/flake-local-settings.sh

@@ -21,7 +21,7 @@ cat <<EOF > flake.nix
     nixConfig.allow-dirty = false; # See #5621
 
     outputs = a: {
-       defaultPackage.$system = import ./simple.nix;
+       packages.$system.default = import ./simple.nix;
     };
 }
 EOF

tests/flake-searching.sh

@@ -15,8 +15,10 @@ cat <<EOF > flake.nix
 {
     inputs.foo.url = "$PWD/foo";
     outputs = a: {
-       defaultPackage.$system = import ./simple.nix;
+       packages.$system = rec {
-       packages.$system.test = import ./simple.nix;
+         test = import ./simple.nix;
+         default = test;
+       };
     };
 }
 EOF

tests/flakes.sh

@@ -41,8 +41,10 @@ cat > $flake1Dir/flake.nix <<EOF
   description = "Bla bla";
 
   outputs = inputs: rec {
-    packages.$system.foo = import ./simple.nix;
+    packages.$system = rec {
-    defaultPackage.$system = packages.$system.foo;
+      foo = import ./simple.nix;
+      default = foo;
+    };
 
     # To test "nix flake init".
     legacyPackages.x86_64-linux.hello = import ./simple.nix;
@@ -128,7 +130,7 @@ hash2=$(nix flake metadata flake1 --json --refresh | jq -r .revision)
 nix build -o $TEST_ROOT/result flake1#foo
 [[ -e $TEST_ROOT/result/hello ]]
 
-# Test defaultPackage.
+# Test packages.default.
 nix build -o $TEST_ROOT/result flake1
 [[ -e $TEST_ROOT/result/hello ]]
 
@@ -140,11 +142,11 @@ nix build -o $flake1Dir/result git+file://$flake1Dir
 nix path-info $flake1Dir/result
 
 # 'getFlake' on a mutable flakeref should fail in pure mode, but succeed in impure mode.
-(! nix build -o $TEST_ROOT/result --expr "(builtins.getFlake \"$flake1Dir\").defaultPackage.$system")
+(! nix build -o $TEST_ROOT/result --expr "(builtins.getFlake \"$flake1Dir\").packages.$system.default")
-nix build -o $TEST_ROOT/result --expr "(builtins.getFlake \"$flake1Dir\").defaultPackage.$system" --impure
+nix build -o $TEST_ROOT/result --expr "(builtins.getFlake \"$flake1Dir\").packages.$system.default" --impure
 
 # 'getFlake' on an immutable flakeref should succeed even in pure mode.
-nix build -o $TEST_ROOT/result --expr "(builtins.getFlake \"git+file://$flake1Dir?rev=$hash2\").defaultPackage.$system"
+nix build -o $TEST_ROOT/result --expr "(builtins.getFlake \"git+file://$flake1Dir?rev=$hash2\").packages.$system.default"
 
 # Building a flake with an unlocked dependency should fail in pure mode.
 (! nix build -o $TEST_ROOT/result flake2#bar --no-registries)
@@ -370,13 +372,13 @@ cat > $templatesDir/flake.nix <<EOF
   description = "Some templates";
 
   outputs = { self }: {
-    templates = {
+    templates = rec {
       trivial = {
         path = ./trivial;
         description = "A trivial flake";
       };
+      default = trivial;
     };
-    defaultTemplate = self.templates.trivial;
   };
 }
 EOF
@@ -388,8 +390,10 @@ cat > $templatesDir/trivial/flake.nix <<EOF
   description = "A flake for building Hello World";
 
   outputs = { self, nixpkgs }: {
-    packages.x86_64-linux.hello = nixpkgs.legacyPackages.x86_64-linux.hello;
+    packages.x86_64-linux = rec {
-    defaultPackage.x86_64-linux = self.packages.x86_64-linux.hello;
+      hello = nixpkgs.legacyPackages.x86_64-linux.hello;
+      default = hello;
+    };
   };
 }
 EOF
@@ -496,17 +500,15 @@ EOF
 cat > $flake3Dir/flake.nix <<EOF
 {
   outputs = { flake1, self }: {
-    defaultPackage = {
+    packages.system-1.default = "foo";
-        system-1 = "foo";
+    packages.system-2.default = "bar";
-        system-2 = "bar";
-    };
   };
 }
 EOF
 
 checkRes=$(nix flake check --keep-going $flake3Dir 2>&1 && fail "nix flake check should have failed" || true)
-echo "$checkRes" | grep -q "defaultPackage.system-1"
+echo "$checkRes" | grep -q "packages.system-1.default"
-echo "$checkRes" | grep -q "defaultPackage.system-2"
+echo "$checkRes" | grep -q "packages.system-2.default"
 
 # Test 'follows' inputs.
 cat > $flake3Dir/flake.nix <<EOF
@@ -591,7 +593,7 @@ mkdir $flake5Dir
 cat > $flake5Dir/flake.nix <<EOF
 {
   outputs = { self, flake1 }: {
-    defaultPackage.$system = flake1.defaultPackage.$system;
+    packages.$system.default = flake1.packages.$system.default;
     expr = assert builtins.pathExists ./flake.lock; 123;
   };
 }