Use a ninja variable for node binary (#2346)

* Use a ninja variable for node binary

* Update docs (dae)

build/ninja_gen/src/node.rs

@@ -114,6 +114,22 @@ pub fn setup_node(
             "npm" => vec![if cfg!(windows) { "npm.cmd " } else { "bin/npm" }]
         },
     )?;
+
+    let node_binary = match std::env::var("NODE_BINARY") {
+        Ok(path) => {
+            assert!(
+                Utf8Path::new(&path).is_absolute(),
+                "NODE_BINARY must be absolute"
+            );
+            path.into()
+        }
+        Err(_) => {
+            inputs![":extract:node:bin"]
+        }
+    };
+    let node_binary = build.expand_inputs(node_binary);
+    build.variable("node_binary", &node_binary[0]);
+
     build.add("yarn", YarnSetup {})?;
 
     for binary in binary_exports {
@@ -148,7 +164,7 @@ impl BuildAction for EsbuildScript<'_> {
     }
 
     fn files(&mut self, build: &mut impl build::FilesHandle) {
-        build.add_inputs("node_bin", inputs![":extract:node:bin"]);
+        build.add_inputs("node_bin", inputs!["$node_binary"]);
         build.add_inputs("script", &self.script);
         build.add_inputs("entrypoint", &self.entrypoint);
         build.add_inputs("", inputs!["yarn.lock", ":node_modules", &self.deps]);

docs/build.md

@@ -34,3 +34,7 @@ If you run into trouble with the build process:
 - You can browse the build graph via e.g. `./ninja -- -t browse wheels`
 - You can profile build performance with
   https://discourse.cmake.org/t/profiling-build-performance/2443/3.
+
+## Packaging considerations
+
+See [this page](./linux.md).

docs/linux.md

@@ -77,9 +77,7 @@ There are a few things to be aware of:
 ## Packaging considerations
 
 Python, node and protoc are downloaded as part of the build. You can optionally define
-PYTHON_BINARY and PROTOC_BINARY as the full path to a Python binary and Protoc binary respectively,
-to use it instead of the downloaded version. A similar approach could be done with node in the future; a PR would be
-welcome.
+PYTHON_BINARY, NODE_BINARY and/or PROTOC_BINARY to use locally-installed versions instead.
 
 If rust-toolchain.toml is removed, newer Rust versions can be used. Older versions
 may or may not compile the code.