add a non-default constructor of WasmBackend

core/src/marine_core.rs

@@ -49,7 +49,7 @@ pub struct MarineCore<WB: WasmBackend> {
 
 impl<WB: WasmBackend> MarineCore<WB> {
     pub fn new() -> Self {
-        let wasm_backend = WB::default();
+        let wasm_backend = WB::new();
         let store = <WB as WasmBackend>::Store::new(&wasm_backend);
         Self {
             modules: HashMap::new(),

crates/marine-wasmtime-backend/src/lib.rs

@@ -91,6 +91,17 @@ impl WasmBackend for WasmtimeWasmBackend {
             inner: module,
         })
     }
+
+    fn new() -> Self {
+        let mut config = wasmtime::Config::new();
+        config
+            .debug_info(true)
+            .wasm_backtrace_details(wasmtime::WasmBacktraceDetails::Enable);
+        let engine = wasmtime::Engine::new(&config).unwrap();
+        Self {
+            engine
+        }
+    }
 }
 
 #[derive(Default)]

crates/wasm-backend-traits/src/lib.rs

@@ -57,6 +57,8 @@ pub trait WasmBackend: Clone + Default + 'static {
     type Wasi: WasiImplementation<Self>;
 
     fn compile(store: &mut Self::Store, wasm: &[u8]) -> CompilationResult<Self::Module>;
+
+    fn new() -> Self;
 }
 
 pub struct DelayedContextLifetime<WB: WasmBackend> {