Exception handling inside async function

[lonerr]

Hi,
It looks that erros happening in asynchronous functions somehow lose their stack.
Please check this minimal reproducible case:

load_module modules/ngx_http_js_module.so;

events {
    worker_connections 1024;
}

http {
    js_import err.js;

    server {
        location = /testAsync {
            js_content err.testAsync;
        }
        location = /testSync {
            js_content err.testSync;
        }
    }
}

The content of err.js is:

async function testAsync(r) {
    try {
        await ngx.fetch('http://127.0.0.1:12345');
    } catch(e) {
        r.return(200, `message: ${e.message}\nstack: ${e.stack}\n`);
    }
}

function testSync(r) {
    try {
        throw Error('oops');
    } catch(e) {
        r.return(200, `message: ${e.message}\nstack: ${e.stack}\n`);
    }
}

export default { testAsync, testSync }

This first result seems perfectly fine:

% curl 127.1/testSync
message: oops
stack: Error: oops
    at testSync (/conf/err.js:11)

But the second doesn't look so good:

% curl 127.1/testAsync
message: connect failed
stack: undefined

Please feel free to reach out to me for any additional details you may require.
Thank you in advance.