fix(coding-agent): keep clipboard helpers out of pi's process group so Ctrl+Z does not stop them

closes #11179

packages/coding-agent/CHANGELOG.md

@@ -18,6 +18,7 @@
 - Fixed HTML export showing literal asterisks for Markdown bold and italic next to CJK punctuation ([#3353](https://github.com/earendil-works/pi/issues/3353), [#10154](https://github.com/earendil-works/pi/issues/10154))
 - Fixed the terminal staying in mouse-tracking, focus-reporting, Kitty keyboard, and alternate-screen modes when pi exits without its normal terminal teardown, which flooded the shell prompt with escape sequences ([#11170](https://github.com/earendil-works/pi/issues/11170))
 - Fixed concurrent extension `select`/`confirm`/`input`/`editor` dialogs and inline `custom()` components in interactive mode: a second dialog replaced the first and the first promise never settled; closing the visible dialog now shows the previous one again ([#11166](https://github.com/earendil-works/pi/issues/11166), [#9909](https://github.com/earendil-works/pi/issues/9909))
+- Fixed pasting in the shell hanging after copying text in pi and suspending it with Ctrl+Z on Linux: the background `wl-copy`/`xclip`/`xsel` process that keeps serving the clipboard was suspended along with pi ([#11179](https://github.com/earendil-works/pi/issues/11179))
 
 ## [1.3.0] - 2026-10-15
 

packages/coding-agent/src/utils/clipboard-command.ts

@@ -8,8 +8,11 @@ export function runClipboardCommand(
 ): Promise<Buffer | undefined> {
 	return new Promise((resolve) => {
 		// Clipboard writers can daemonize. Do not give them output pipes to retain.
+		// Detach on POSIX so the daemon leaves pi's process group and Ctrl+Z suspend
+		// (SIGTSTP to the group) does not stop the clipboard owner (#11179).
 		const child = spawn(command, args, {
 			stdio: ["pipe", options?.input === undefined ? "pipe" : "ignore", "ignore"],
+			detached: process.platform !== "win32",
 			windowsHide: true,
 		});
 		const chunks: Buffer[] = [];

packages/coding-agent/test/clipboard-command.test.ts

@@ -29,6 +29,16 @@ describe("clipboard commands", () => {
 			clearInterval(timer);
 		}
 	});
+	// #11179: clipboard daemons must not share pi's process group, or Ctrl+Z suspend stops them.
+	test.skipIf(process.platform === "win32")("runs commands outside pi's process group", async () => {
+		const childPgid = (await runClipboardCommand("sh", ["-c", "ps -o pgid= -p $$"]))?.toString("utf8").trim();
+		const ownPgid = (await runClipboardCommand("ps", ["-o", "pgid=", "-p", String(process.pid)]))
+			?.toString("utf8")
+			.trim();
+		expect(childPgid).toMatch(/^\d+$/);
+		expect(ownPgid).toMatch(/^\d+$/);
+		expect(childPgid).not.toBe(ownPgid);
+	});
 	test("rejects output above the buffer limit", async () => {
 		expect(
 			await runClipboardCommand(process.execPath, ["-e", "process.stdout.write(Buffer.alloc(1024))"], {