Memory leak: process.stdin event listeners never removed in ACP command

[riftzen-bit]

Summary

The ACP (Agent Communication Protocol) command adds event listeners to process.stdin that are never removed, causing a memory leak in long-running processes.

Location

packages/opencode/src/cli/cmd/acp.ts:47-67

Issue

The code adds multiple listeners to process.stdin but never removes them:

// First set of listeners at lines 47-51
process.stdin.on("data", (chunk: Buffer) => {
  controller.enqueue(new Uint8Array(chunk))
})
process.stdin.on("end", () => controller.close())
process.stdin.on("error", (err) => controller.error(err))

// ... later, DUPLICATE listeners are added at lines 64-66
await new Promise((resolve, reject) => {
  process.stdin.on("end", resolve)    // Duplicate!
  process.stdin.on("error", reject)   // Duplicate!
})

Impact

• Severity: Medium
• Type: Memory Leak
• Affected: Long-running ACP processes

Suggested Fix

Use once() for listeners that should only fire once:

await new Promise((resolve, reject) => {
  process.stdin.once("end", resolve)
  process.stdin.once("error", reject)
})

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Memory leak: ACP session event streams never aborted #9154: Memory leak: ACP session event streams never aborted - This is also about memory leaks in ACP and involves event listener cleanup issues

Feel free to ignore if this doesn't address your specific case.

[thdxr]

Closing in favor of #20695 where we're collecting all memory-related problems. Please follow that issue for updates.