Bash tool hangs indefinitely when executing commands that launch daemon processes with continuous output #42524

Description

When the agent executes a command that launches a daemon process (e.g., uvicorn, npm run dev, docker compose up) with continuous stdout/stderr output, the Bash tool hangs indefinitely and never returns. The agent gets stuck in a loading/spinning state, appearing to be in an infinite loop, even though the foreground command has completed.

The root cause appears to be that the Node.js child process close event only fires after all stdio streams are closed. Since daemon processes inherit the parent pipe and continuously write to stdout/stderr, these streams never close, causing OpenCode to wait forever.

This issue is reproducible with commands like:

uvicorn demo_server:app &

npm run dev & (for frameworks like Vite, Next.js)

docker compose up -d (may also trigger similar behavior if logs are being streamed)

Plugins

OmO — The Best Agent Harness

OpenCode version

1.18.9

Steps to reproduce

Run a command in the agent that starts a daemon process with continuous output, e.g.:

text
uvicorn demo_server:app &
Observe that the foreground command completes (the shell prompt returns).

The Bash tool in OpenCode does not complete and continues spinning indefinitely.

No further agent actions can proceed.

Screenshot and/or share link

No response

Operating System

Windows 11

Terminal

powershell