Avoid leaking Nixify env setting

Bump actions/setup-node from 4.1.0 to 4.2.0

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Node.js
-        uses: actions/setup-node@v4.0.4
+        uses: actions/setup-node@v4.2.0
         with:
           node-version: 18.x
 
@@ -99,7 +99,8 @@ jobs:
             src = ./.;
             overrideSqlite3Attrs = old: {
               npm_config_sqlite = "/";  # Don't accidentally use the wrong sqlite.
-              buildInputs = old.buildInputs ++ (with pkgs; [ python3 sqlite ]);
+              nativeBuildInputs = [ pkgs.python311 ];
+              buildInputs = old.buildInputs ++ [ pkgs.sqlite ];
             };
           }
           EOF

ISOLATED_BUILDS.md

@@ -23,7 +23,8 @@ pkgs.callPackage ./yarn-project.nix { } {
   src = ./.;
   overrideSqlite3Attrs = old: {
     npm_config_sqlite = "/";  # Don't accidentally use the wrong sqlite.
-    buildInputs = old.buildInputs ++ (with pkgs; [ python3 sqlite ]);
+    nativeBuildInputs = [ pkgs.python311 ];
+    buildInputs = old.buildInputs ++ [ pkgs.sqlite ];
   };
 }
 ```

src/generate.ts

@@ -395,6 +395,7 @@ export default async (
       USES_PNP_LINKER: configuration.get("nodeLinker") === "pnp",
       USES_NM_LINKER: configuration.get("nodeLinker") === "node-modules",
     }).replace(/\n\n\n+/g, "\n\n");
+    await xfs.mkdirpPromise(ppath.dirname(nixExprPath));
     await xfs.writeFilePromise(nixExprPath, projectExpr);
 
     // Create a wrapper if it does not exist yet.

src/tmpl/yarn-project.nix.in

@@ -36,8 +36,6 @@ let
     export CI=1
     # Tell node-pre-gyp to never fetch binaries / always build from source.
     export npm_config_build_from_source=true
-    # Disable Nixify plugin to save on some unnecessary processing.
-    export yarn_enable_nixify=false
   '';
 
 #@@ IF COMBINED_DRV
@@ -66,7 +64,7 @@ let
       cd '${src}'
       ${buildVars}
       HOME="$TMP" yarn_enable_global_cache=false yarn_cache_folder="$TMP" \
-        yarn nixify fetch ${locator}
+        yarn nixify fetch ${lib.escapeShellArg locator}
       # Because we change the cache dir, Yarn may generate a different name.
       mv "$TMP/$(sed 's/-[^-]*\.[^-]*$//' <<< "$outputFilename")"-* $out
     '';