diff --git a/build/ninja_gen/src/render.rs b/build/ninja_gen/src/render.rs
index a9a32cf84..4c83e382f 100644
--- a/build/ninja_gen/src/render.rs
+++ b/build/ninja_gen/src/render.rs
@@ -22,17 +22,12 @@ impl Build {
         )
         .unwrap();
 
-        writeln!(&mut buf, "builddir = {}", self.buildroot.as_str()).unwrap();
         writeln!(
             &mut buf,
             "runner = $builddir/rust/release/{}",
             with_exe("runner")
         )
         .unwrap();
-        for (key, value) in &self.variables {
-            writeln!(&mut buf, "{} = {}", key, value).unwrap();
-        }
-        buf.push('\n');
 
         for (key, value) in &self.pools {
             writeln!(&mut buf, "pool {}\n  depth = {}", key, value).unwrap();
@@ -54,6 +49,14 @@ impl Build {
 
         buf.push_str(&self.trailing_text);
 
+        buf = buf.replace("$builddir", self.buildroot.as_str());
+        for (key, value) in &self.variables {
+            buf = buf.replace(
+                &format!("${key}"),
+                &value.replace("$builddir", self.buildroot.as_str()),
+            );
+        }
+
         buf
     }
 
diff --git a/tools/install-n2 b/tools/install-n2
index d4ef988aa..a87017954 100755
--- a/tools/install-n2
+++ b/tools/install-n2
@@ -1,3 +1,3 @@
 #!/bin/bash
 
-cargo install --git https://github.com/ankitects/n2.git --rev 3eca2545a8f4c8cbdd8ed697936bd2ae929b55dd
+cargo install --git https://github.com/ankitects/n2.git --rev 56202604d4c541524b82381162eafae4290fdd22