fix(tui): prevent UI freezes from clipboard operations and event loop

- Replace Bun.$ with node:child_process in clipboard.ts to avoid GC crashes
- Add debouncing to clipboard copy operations (100ms)
- Add yield point in SDK event loop to prevent render thread starvation

Addresses Bun shell GC bug: oven-sh/bun#23177

Author: coleleavitt

packages/opencode/src/cli/cmd/tui/app.tsx

@@ -1,6 +1,24 @@
 import { render, useKeyboard, useRenderer, useTerminalDimensions } from "@opentui/solid"
 import { Clipboard } from "@tui/util/clipboard"
 import { TextAttributes } from "@opentui/core"
+
+let copyDebounceTimer: Timer | undefined
+let lastCopyTime = 0
+const COPY_DEBOUNCE_MS = 100
+
+function debouncedCopy(text: string, onSuccess?: () => void, onError?: (e: unknown) => void): void {
+  const now = Date.now()
+  if (now - lastCopyTime < COPY_DEBOUNCE_MS) {
+    if (copyDebounceTimer) clearTimeout(copyDebounceTimer)
+    copyDebounceTimer = setTimeout(() => {
+      lastCopyTime = Date.now()
+      Clipboard.copy(text).then(onSuccess).catch(onError)
+    }, COPY_DEBOUNCE_MS)
+    return
+  }
+  lastCopyTime = now
+  Clipboard.copy(text).then(onSuccess).catch(onError)
+}
 import { RouteProvider, useRoute } from "@tui/context/route"
 import { Switch, Match, createEffect, untrack, ErrorBoundary, createSignal, onMount, batch, Show, on } from "solid-js"
 import { Installation } from "@/installation"
@@ -156,9 +174,9 @@ export function tui(input: { url: string; args: Args; directory?: string; onExit
         consoleOptions: {
           keyBindings: [{ name: "y", ctrl: true, action: "copy-selection" }],
           onCopySelection: (text) => {
-            Clipboard.copy(text).catch((error) => {
-              console.error(`Failed to copy console selection to clipboard: ${error}`)
-            })
+            debouncedCopy(text, undefined, (error) =>
+              console.error(`Failed to copy console selection to clipboard: ${error}`),
+            )
           },
         },
       },
@@ -182,18 +200,15 @@ function App() {
   const exit = useExit()
   const promptRef = usePromptRef()
 
-  // Wire up console copy-to-clipboard via opentui's onCopySelection callback
-  renderer.console.onCopySelection = async (text: string) => {
+  renderer.console.onCopySelection = (text: string) => {
     if (!text || text.length === 0) return
 
     const base64 = Buffer.from(text).toString("base64")
     const osc52 = `\x1b]52;c;${base64}\x07`
     const finalOsc52 = process.env["TMUX"] ? `\x1bPtmux;\x1b${osc52}\x1b\\` : osc52
     // @ts-expect-error writeOut is not in type definitions
     renderer.writeOut(finalOsc52)
-    await Clipboard.copy(text)
-      .then(() => toast.show({ message: "Copied to clipboard", variant: "info" }))
-      .catch(toast.error)
+    debouncedCopy(text, () => toast.show({ message: "Copied to clipboard", variant: "info" }), toast.error)
     renderer.clearSelection()
   }
   const [terminalTitleEnabled, setTerminalTitleEnabled] = createSignal(kv.get("terminal_title_enabled", true))
@@ -615,7 +630,7 @@ function App() {
       width={dimensions().width}
       height={dimensions().height}
       backgroundColor={theme.background}
-      onMouseUp={async () => {
+      onMouseUp={() => {
         if (Flag.OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT) {
           renderer.clearSelection()
           return
@@ -627,9 +642,7 @@ function App() {
           const finalOsc52 = process.env["TMUX"] ? `\x1bPtmux;\x1b${osc52}\x1b\\` : osc52
           /* @ts-expect-error */
           renderer.writeOut(finalOsc52)
-          await Clipboard.copy(text)
-            .then(() => toast.show({ message: "Copied to clipboard", variant: "info" }))
-            .catch(toast.error)
+          debouncedCopy(text, () => toast.show({ message: "Copied to clipboard", variant: "info" }), toast.error)
           renderer.clearSelection()
         }
       }}
@@ -693,9 +706,7 @@ function ErrorComponent(props: {
   issueURL.searchParams.set("opencode-version", Installation.VERSION)
 
   const copyIssueURL = () => {
-    Clipboard.copy(issueURL.toString()).then(() => {
-      setCopied(true)
-    })
+    debouncedCopy(issueURL.toString(), () => setCopied(true))
   }
 
   return (

packages/opencode/src/cli/cmd/tui/context/sdk.tsx

@@ -49,13 +49,12 @@ export const { use: useSDK, provider: SDKProvider } = createSimpleContext({
           const elapsed = Date.now() - last
 
           if (timer) continue
-          // If we just flushed recently (within 16ms), batch this with future events
-          // Otherwise, process immediately to avoid latency
           if (elapsed < 16) {
             timer = setTimeout(flush, 16)
             continue
           }
           flush()
+          await new Promise((r) => setTimeout(r, 0))
         }
 
         // Flush any remaining events

packages/opencode/src/cli/cmd/tui/util/clipboard.ts

@@ -1,10 +1,57 @@
-import { $ } from "bun"
+import { spawn, execSync } from "node:child_process"
 import { platform, release } from "os"
 import clipboardy from "clipboardy"
 import { lazy } from "../../../../util/lazy.js"
 import { tmpdir } from "os"
 import path from "path"
 
+function runCommand(cmd: string, args: string[]): Promise<Buffer | undefined> {
+  return new Promise((resolve) => {
+    const proc = spawn(cmd, args, { stdio: ["ignore", "pipe", "ignore"] })
+    const chunks: Buffer[] = []
+    proc.stdout.on("data", (chunk) => chunks.push(chunk))
+    proc.on("close", (code) => {
+      if (code === 0 && chunks.length > 0) {
+        resolve(Buffer.concat(chunks))
+      } else {
+        resolve(undefined)
+      }
+    })
+    proc.on("error", () => resolve(undefined))
+  })
+}
+
+function runCommandText(cmd: string, args: string[]): Promise<string | undefined> {
+  return runCommand(cmd, args).then((buf) => buf?.toString("utf-8"))
+}
+
+function writeToCommand(cmd: string, args: string[], data: string): Promise<void> {
+  return new Promise((resolve) => {
+    const proc = spawn(cmd, args, { stdio: ["pipe", "ignore", "ignore"] })
+    proc.stdin.write(data)
+    proc.stdin.end()
+    proc.on("close", () => resolve())
+    proc.on("error", () => resolve())
+  })
+}
+
+function execQuiet(cmd: string): Promise<void> {
+  return new Promise((resolve) => {
+    const proc = spawn("sh", ["-c", cmd], { stdio: "ignore" })
+    proc.on("close", () => resolve())
+    proc.on("error", () => resolve())
+  })
+}
+
+function which(cmd: string): boolean {
+  try {
+    execSync(`which ${cmd}`, { stdio: "ignore" })
+    return true
+  } catch {
+    return false
+  }
+}
+
 export namespace Clipboard {
   export interface Content {
     data: string
@@ -17,38 +64,42 @@ export namespace Clipboard {
     if (os === "darwin") {
       const tmpfile = path.join(tmpdir(), "opencode-clipboard.png")
       try {
-        await $`osascript -e 'set imageData to the clipboard as "PNGf"' -e 'set fileRef to open for access POSIX file "${tmpfile}" with write permission' -e 'set eof fileRef to 0' -e 'write imageData to fileRef' -e 'close access fileRef'`
-          .nothrow()
-          .quiet()
+        await execQuiet(
+          `osascript -e 'set imageData to the clipboard as "PNGf"' -e 'set fileRef to open for access POSIX file "${tmpfile}" with write permission' -e 'set eof fileRef to 0' -e 'write imageData to fileRef' -e 'close access fileRef'`,
+        )
         const file = Bun.file(tmpfile)
-        const buffer = await file.arrayBuffer()
-        return { data: Buffer.from(buffer).toString("base64"), mime: "image/png" }
+        if (await file.exists()) {
+          const buffer = await file.arrayBuffer()
+          if (buffer.byteLength > 0) {
+            return { data: Buffer.from(buffer).toString("base64"), mime: "image/png" }
+          }
+        }
       } catch {
       } finally {
-        await $`rm -f "${tmpfile}"`.nothrow().quiet()
+        await execQuiet(`rm -f "${tmpfile}"`)
       }
     }
 
     if (os === "win32" || release().includes("WSL")) {
       const script =
         "Add-Type -AssemblyName System.Windows.Forms; $img = [System.Windows.Forms.Clipboard]::GetImage(); if ($img) { $ms = New-Object System.IO.MemoryStream; $img.Save($ms, [System.Drawing.Imaging.ImageFormat]::Png); [System.Convert]::ToBase64String($ms.ToArray()) }"
-      const base64 = await $`powershell.exe -NonInteractive -NoProfile -command "${script}"`.nothrow().text()
-      if (base64) {
-        const imageBuffer = Buffer.from(base64.trim(), "base64")
+      const result = await runCommandText("powershell.exe", ["-NonInteractive", "-NoProfile", "-command", script])
+      if (result) {
+        const imageBuffer = Buffer.from(result.trim(), "base64")
         if (imageBuffer.length > 0) {
           return { data: imageBuffer.toString("base64"), mime: "image/png" }
         }
       }
     }
 
     if (os === "linux") {
-      const wayland = await $`wl-paste -t image/png`.nothrow().arrayBuffer()
+      const wayland = await runCommand("wl-paste", ["-t", "image/png"])
       if (wayland && wayland.byteLength > 0) {
-        return { data: Buffer.from(wayland).toString("base64"), mime: "image/png" }
+        return { data: wayland.toString("base64"), mime: "image/png" }
       }
-      const x11 = await $`xclip -selection clipboard -t image/png -o`.nothrow().arrayBuffer()
+      const x11 = await runCommand("xclip", ["-selection", "clipboard", "-t", "image/png", "-o"])
       if (x11 && x11.byteLength > 0) {
-        return { data: Buffer.from(x11).toString("base64"), mime: "image/png" }
+        return { data: x11.toString("base64"), mime: "image/png" }
       }
     }
 
@@ -61,58 +112,40 @@ export namespace Clipboard {
   const getCopyMethod = lazy(() => {
     const os = platform()
 
-    if (os === "darwin" && Bun.which("osascript")) {
+    if (os === "darwin" && which("osascript")) {
       console.log("clipboard: using osascript")
       return async (text: string) => {
         const escaped = text.replace(/\\/g, "\\\\").replace(/"/g, '\\"')
-        await $`osascript -e 'set the clipboard to "${escaped}"'`.nothrow().quiet()
+        await execQuiet(`osascript -e 'set the clipboard to "${escaped}"'`)
       }
     }
 
     if (os === "linux") {
-      if (process.env["WAYLAND_DISPLAY"] && Bun.which("wl-copy")) {
+      if (process.env["WAYLAND_DISPLAY"] && which("wl-copy")) {
         console.log("clipboard: using wl-copy")
         return async (text: string) => {
-          const proc = Bun.spawn(["wl-copy"], { stdin: "pipe", stdout: "ignore", stderr: "ignore" })
-          proc.stdin.write(text)
-          proc.stdin.end()
-          await proc.exited.catch(() => {})
+          await writeToCommand("wl-copy", [], text)
         }
       }
-      if (Bun.which("xclip")) {
+      if (which("xclip")) {
         console.log("clipboard: using xclip")
         return async (text: string) => {
-          const proc = Bun.spawn(["xclip", "-selection", "clipboard"], {
-            stdin: "pipe",
-            stdout: "ignore",
-            stderr: "ignore",
-          })
-          proc.stdin.write(text)
-          proc.stdin.end()
-          await proc.exited.catch(() => {})
+          await writeToCommand("xclip", ["-selection", "clipboard"], text)
         }
       }
-      if (Bun.which("xsel")) {
+      if (which("xsel")) {
         console.log("clipboard: using xsel")
         return async (text: string) => {
-          const proc = Bun.spawn(["xsel", "--clipboard", "--input"], {
-            stdin: "pipe",
-            stdout: "ignore",
-            stderr: "ignore",
-          })
-          proc.stdin.write(text)
-          proc.stdin.end()
-          await proc.exited.catch(() => {})
+          await writeToCommand("xsel", ["--clipboard", "--input"], text)
         }
       }
     }
 
     if (os === "win32") {
       console.log("clipboard: using powershell")
       return async (text: string) => {
-        // need to escape backticks because powershell uses them as escape code
         const escaped = text.replace(/"/g, '""').replace(/`/g, "``")
-        await $`powershell -NonInteractive -NoProfile -Command "Set-Clipboard -Value \"${escaped}\""`.nothrow().quiet()
+        await execQuiet(`powershell -NonInteractive -NoProfile -Command "Set-Clipboard -Value \\"${escaped}\\""`)
       }
     }