diff --git a/rust/nix-expr/src/eval_state.rs b/rust/nix-expr/src/eval_state.rs
index e558f1b..c929278 100644
--- a/rust/nix-expr/src/eval_state.rs
+++ b/rust/nix-expr/src/eval_state.rs
@@ -248,20 +248,17 @@ mod tests {
 
     #[ctor]
     fn setup() {
-        (|| -> Result<()> {
-            init()?;
-            // During development, we encountered a problem where the build hook
-            // would cause the test suite to reinvokes itself, causing an infinite loop.
-            // While _NIX_TEST_NO_SANDBOX=1 should prevent this, we may also set the
-            // build hook to "" to prevent this.
-            // settings::set("build-hook", "")?;
+        init().unwrap();
 
-            // When testing in the sandbox, the default build dir would be a parent of the storeDir,
-            // which causes an error. So we set a custom build dir here.
-            settings::set("sandbox-build-dir", "/custom-build-dir-for-test")?;
-            Ok(())
-        })()
-        .unwrap();
+        // During development, we encountered a problem where the build hook
+        // would cause the test suite to reinvokes itself, causing an infinite loop.
+        // While _NIX_TEST_NO_SANDBOX=1 should prevent this, we may also set the
+        // build hook to "" to prevent this.
+        // settings::set("build-hook", "")?;
+
+        // When testing in the sandbox, the default build dir would be a parent of the storeDir,
+        // which causes an error. So we set a custom build dir here.
+        settings::set("sandbox-build-dir", "/custom-build-dir-for-test").unwrap();
         std::env::set_var("_NIX_TEST_NO_SANDBOX", "1");
     }