diff --git a/host/src/world.rs b/host/src/world.rs
index 2a6f79d..7231b19 100644
--- a/host/src/world.rs
+++ b/host/src/world.rs
@@ -105,21 +105,36 @@ fn readonly_bundle_copies_are_writable() -> std::io::Result<()> {
         fs::write(&path, b"original")?;
         fs::set_permissions(path, fs::Permissions::from_mode(mode))?;
     }
-    for path in [bundle.path().join("bin"), bundle.path().join("src"), bundle.path().to_owned(), world.path().to_owned()] {
+    for path in [
+        bundle.path().join("bin"),
+        bundle.path().join("src"),
+        bundle.path().to_owned(),
+        world.path().to_owned(),
+    ] {
         fs::set_permissions(path, fs::Permissions::from_mode(0o555))?;
     }
     let result = copy_tree(bundle.path(), world.path());
     // Restore source directories so the temporary directory can remove its files.
-    for path in [bundle.path(), &bundle.path().join("bin"), &bundle.path().join("src")] {
+    for path in [
+        bundle.path(),
+        &bundle.path().join("bin"),
+        &bundle.path().join("src"),
+    ] {
         fs::set_permissions(path, fs::Permissions::from_mode(0o755))?;
     }
     result?;
-    assert_eq!(fs::metadata(world.path())?.permissions().mode() & 0o777, 0o755);
+    assert_eq!(
+        fs::metadata(world.path())?.permissions().mode() & 0o777,
+        0o755
+    );
     for (name, mode) in [("bin/tool.wasm", 0o555), ("src/lib.rs", 0o444)] {
         let source = bundle.path().join(name);
         let target = world.path().join(name);
         assert_eq!(fs::metadata(&source)?.permissions().mode() & 0o777, mode);
-        assert_eq!(fs::metadata(&target)?.permissions().mode() & 0o777, mode | 0o200);
+        assert_eq!(
+            fs::metadata(&target)?.permissions().mode() & 0o777,
+            mode | 0o200
+        );
         fs::write(&target, b"changed")?;
         assert_eq!(fs::read(source)?, b"original");
     }