Fix

crates/hir-def/src/body/lower.rs

@@ -655,13 +655,30 @@ impl ExprCollector<'_> {
                     };
                     ClosureKind::Coroutine(crate::hir::CoroutineKind::Coroutine, movability)
                 } else if e.async_token().is_some() {
-                    ClosureKind::Coroutine(
+                    // https://github.com/compiler-errors/rust/blob/bd0eec74026d5f967afeadc3611bdb674a7b9de4/compiler/rustc_ast_lowering/src/expr.rs#L1199 ?
+
+                    let capture_by =
+                        if e.move_token().is_some() { CaptureBy::Value } else { CaptureBy::Ref };
+
+                    let inner = Expr::Closure { args: Box::new([]), arg_types: Box::new([]), ret_type: ret_type.clone(), body, closure_kind: ClosureKind::Coroutine(
                         crate::hir::CoroutineKind::Desugared(
                             crate::hir::CoroutineDesugaring::Async,
                             crate::hir::CoroutineSource::Closure,
                         ),
                         Movability::Movable,
-                    )
+                    ), capture_by };
+  this.is_lowering_generator = prev_is_lowering_generator;
+                    this.current_binding_owner = prev_binding_owner;
+                    this.current_try_block_label = prev_try_block_label;
+                    this.body.exprs[result_expr_id] = Expr::Closure {
+                        args: args.into(),
+                        arg_types: arg_types.into(),
+                        ret_type,
+                        body: this.alloc_expr_desugared(inner),
+                        closure_kind: ClosureKind::Closure,
+                        capture_by,
+                    };
+                    return result_expr_id
                 } else {
                     ClosureKind::Closure
                 };