Deno.listen fails when transpiled at runtime

[sigmaSd]

mod.ts

export function server(port = 4221) {
  const listener = Deno.listen({ port });
  (async () => {
    for await (const conn of listener) {
      conn.readable.pipeTo(conn.writable);
    }
  })();
  return listener;
}

mod.test.ts

import { server } from "./mod.ts";
import { assertEquals } from "https://deno.land/std@0.204.0/assert/mod.ts";

const E = new TextEncoder();
const D = new TextDecoder();
Deno.test("smoke", async () => {
  const listner = server(4221);
  const con = await Deno.connect({ port: 4221 });
  await con.write(E.encode("hello"));
  const ans = new Uint8Array(5);
  await con.read(ans);
  assertEquals(D.decode(ans), "hello");
  listner.close();
  con.close();
  // give time for the listner loop to end
  await new Promise((r) => setTimeout(r, 100));
});

build.ts

// ex. scripts/build_npm.ts
import { build, emptyDir } from "https://deno.land/x/dnt@0.38.1/mod.ts";

await emptyDir("./npm");

await build({
  entryPoints: ["./mod.ts"],
  outDir: "./npm",
  shims: {
    // see JS docs for overview and more options
    deno: true,
  },
  package: {
    // package.json properties
    name: "http-server",
    version: Deno.args[0],
    description: "Http Server",
    license: "MIT",
  },
  postBuild() {
    // steps to run after building and before running the tests
    // Deno.copyFileSync("LICENSE", "npm/LICENSE");
    // Deno.copyFileSync("README.md", "npm/README.md");
  },
});

deno run -A build.ts

error

[dnt] Transforming...
[dnt] Running npm install...

added 7 packages, and audited 8 packages in 6s

found 0 vulnerabilities
[dnt] Building project...
[dnt] Type checking ESM...
[dnt] Emitting ESM package...
[dnt] Emitting script package...
[dnt] Running post build action...
[dnt] Running tests...

> test
> node test_runner.js

Running tests in ./script/mod.test.js...

test smoke ... fail

FAILURES

smoke
  TypeError: Cannot read properties of null (reading 'fd')
      at Object.listen (/home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/npm/node_modules/@deno/shim-deno/dist/deno/stable/functions/listen.js:44:64)
      at server (/home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/npm/script/mod.js:29:35)
      at Object.fn (/home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/npm/script/mod.test.js:32:41)
      at runTestDefinitions (/home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/npm/test_runner.js:54:30)
      at main (/home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/npm/test_runner.js:31:15)
      at Object.<anonymous> (/home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/npm/test_runner.js:198:1)
      at Module._compile (node:internal/modules/cjs/loader:1256:14)
      at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
      at Module.load (node:internal/modules/cjs/loader:1119:32)
      at Module._load (node:internal/modules/cjs/loader:960:12)error: Uncaught (in promise) Error: npm run test failed with exit code 1
      throw new Error(
            ^
    at runCommand (https://deno.land/x/dnt@0.38.1/lib/utils.ts:56:13)
    at eventLoopTick (ext:core/01_core.js:183:11)
    at async build (https://deno.land/x/dnt@0.38.1/mod.ts:407:5)
    at async file:///home/mrcool/dev/codecraft/codecrafters-http-server-javascript/deno/scripts/build.ts:6:1