1.0.0-beta10: HTTP responses hang or return empty body with elide serve (regression vs beta9 preinit crash)

[akapug]

Summary

• On 1.0.0-beta10, elide serve accepts connections and routes requests, but HTTP responses either hang indefinitely (no body transmitted) or return 200 OK with empty body. On 1.0.0-beta9, elide serve crashed on startup due to a Graal preinit error; that is fixed in beta10 but appears to have regressed the HTTP pipeline.

Environment

• Elide CLI: 1.0.0-beta10 (linux-amd64) installed via: curl -sSL --tlsv1.2 elide.sh | bash -s - --install-rev=1.0.0-beta10
• Host OS: Linux x86_64 (ThinkPad T14 Gen1, 32GB RAM)
• Java/Graal: Oracle GraalVM v25.0.0 (reported by elide info --verbose)
• Transport: EpollTransport (auto-selected; logs show "Using transport: EpollTransport")
• curl: 8.14.1

Expected

• "elide serve ./hello.mjs" should return the body (e.g., "Hello!") promptly.

Actual

• Server starts and logs show requests being handled (pipeline stage 0 matched), but client hangs waiting for body. In some runs, headers are sent (HTTP/1.1 200 OK) but body is empty or truncated. Previously saw Netty ByteBuf leak warnings when experimenting.

Repro (minimal)

1. hello.mjs

export default {
  async fetch(_req) {
    return new Response("Hello!", { status: 200 });
  }
};

2. hello_json.mjs

export default {
  async fetch(_req) {
    return Response.json({ ok: true, t: Date.now() });
  }
};

3. Run

elide --version  # -> 1.0.0-beta10
elide --debug serve ./hello.mjs   # or ./hello_json.mjs
curl -iS http://127.0.0.1:8080/

Observed logs (excerpt)

Server listening at 0.0.0.0/0.0.0.0:8080
Handling HTTP request: ... GET /
Handling pipeline stage: 0
Handler condition matches request at stage 0
Resolving context for current thread
No cached context found for current thread, acquiring new context
... (VFS checks)
# No subsequent log indicating response write/flush; curl hangs waiting for body

Notes

• beta9: startup failed with Graal preinit NPE in PolyglotContextImpl.loadPreinitializedContext (fixed by beta10).
• beta10: startup succeeds; responses now hang/empty. Appears to be in the HTTP response pipeline.
• I also tried:
  • Explicit Content-Length and Content-Type headers (server sometimes failed to start or behavior unchanged)
  • Response.json()
  • Different handlers (string, JSON); all hang
  • --debug, which shows request handling but not response emission
  • The transport selected was EpollTransport; if there is a switch to force NIO, happy to try.

Questions / Request

• Is this a known issue on beta10? Any flags/workarounds to force a different Netty transport or disable certain pipeline features?
• Happy to run a patched snapshot or provide more logs. I can also try a specific JAVA_TOOL_OPTIONS/System properties if advised.

Thanks!

[sgammon]

@darvld

[darvld]

Treating this as a known issue with the current engine for now, it will be addressed by the new implementation (which also fixes #1693)