fix: redirect all @InQuirer prompts to stderr to prevent arb cd hanging

When shell integration is active, `arb cd` (without arguments) hangs
because the shell wrapper captures stdout via command substitution,
turning it into a pipe. @inquirer/select renders its interactive UI to
stdout by default, so the user never sees the prompt.

Pass `{ output: process.stderr }` as the context argument to all 12
@InQuirer calls across the codebase. Also strengthen the TTY guard in
cd.ts to check `process.stderr.isTTY` since that is now where the UI
renders.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: henrikje

src/commands/cd.ts

@@ -16,7 +16,7 @@ export function registerCdCommand(program: Command, getCtx: () => ArbContext): v
 			const ctx = getCtx();
 
 			if (!input) {
-				if (!process.stdin.isTTY) {
+				if (!process.stdin.isTTY || !process.stderr.isTTY) {
 					error("Usage: arb cd <workspace>");
 					process.exit(1);
 				}
@@ -27,11 +27,14 @@ export function registerCdCommand(program: Command, getCtx: () => ArbContext): v
 					process.exit(1);
 				}
 
-				const selected = await select({
-					message: "Select a workspace",
-					choices: workspaces.map((name) => ({ name, value: name })),
-					pageSize: 20,
-				});
+				const selected = await select(
+					{
+						message: "Select a workspace",
+						choices: workspaces.map((name) => ({ name, value: name })),
+						pageSize: 20,
+					},
+					{ output: process.stderr },
+				);
 
 				process.stdout.write(`${ctx.baseDir}/${selected}\n`);
 				printHintIfNeeded();

src/commands/create.ts

@@ -39,10 +39,13 @@ export function registerCreateCommand(program: Command, getCtx: () => ArbContext
 						error("Usage: arb create <name> [repos...]");
 						process.exit(1);
 					}
-					name = await input({
-						message: "Workspace name:",
-						validate: (v) => validateWorkspaceName(v) ?? true,
-					});
+					name = await input(
+						{
+							message: "Workspace name:",
+							validate: (v) => validateWorkspaceName(v) ?? true,
+						},
+						{ output: process.stderr },
+					);
 				}
 
 				const validationError = validateWorkspaceName(name);
@@ -55,11 +58,14 @@ export function registerCreateCommand(program: Command, getCtx: () => ArbContext
 				if (!branch) {
 					const defaultBranch = name.toLowerCase();
 					if (!nameArg && process.stdin.isTTY) {
-						branch = await input({
-							message: "Branch name:",
-							default: defaultBranch,
-							validate: (v) => (validateBranchName(v) ? true : "Invalid branch name"),
-						});
+						branch = await input(
+							{
+								message: "Branch name:",
+								default: defaultBranch,
+								validate: (v) => (validateBranchName(v) ? true : "Invalid branch name"),
+							},
+							{ output: process.stderr },
+						);
 					} else {
 						branch = defaultBranch;
 					}
@@ -72,9 +78,12 @@ export function registerCreateCommand(program: Command, getCtx: () => ArbContext
 
 				let base = options.base;
 				if (!base && !nameArg && process.stdin.isTTY) {
-					const baseInput = await input({
-						message: "Base branch (leave blank for repo default):",
-					});
+					const baseInput = await input(
+						{
+							message: "Base branch (leave blank for repo default):",
+						},
+						{ output: process.stderr },
+					);
 					if (baseInput.trim()) {
 						base = baseInput.trim();
 					}

src/commands/pull.ts

@@ -96,10 +96,13 @@ export function registerPullCommand(program: Command, getCtx: () => ArbContext):
 					error("Not a terminal. Use --yes to skip confirmation.");
 					process.exit(1);
 				}
-				const ok = await confirm({
-					message: `Pull ${plural(willPull.length, "repo")}?`,
-					default: false,
-				});
+				const ok = await confirm(
+					{
+						message: `Pull ${plural(willPull.length, "repo")}?`,
+						default: false,
+					},
+					{ output: process.stderr },
+				);
 				if (!ok) {
 					process.stderr.write("Aborted.\n");
 					process.exit(130);

src/commands/push.ts

@@ -89,10 +89,13 @@ export function registerPushCommand(program: Command, getCtx: () => ArbContext):
 					error("Not a terminal. Use --yes to skip confirmation.");
 					process.exit(1);
 				}
-				const ok = await confirm({
-					message: `Push ${plural(willPush.length, "repo")}?`,
-					default: false,
-				});
+				const ok = await confirm(
+					{
+						message: `Push ${plural(willPush.length, "repo")}?`,
+						default: false,
+					},
+					{ output: process.stderr },
+				);
 				if (!ok) {
 					process.stderr.write("Aborted.\n");
 					process.exit(130);

src/commands/remove.ts

@@ -286,10 +286,13 @@ export function registerRemoveCommand(program: Command, getCtx: () => ArbContext
 						error("Cannot prompt for confirmation: not a terminal. Use --force to skip prompts.");
 						process.exit(1);
 					}
-					const shouldRemove = await confirm({
-						message: `Remove ${plural(okEntries.length, "workspace")}?`,
-						default: false,
-					});
+					const shouldRemove = await confirm(
+						{
+							message: `Remove ${plural(okEntries.length, "workspace")}?`,
+							default: false,
+						},
+						{ output: process.stderr },
+					);
 					if (!shouldRemove) {
 						process.stderr.write("Aborted.\n");
 						return;
@@ -368,15 +371,18 @@ export function registerRemoveCommand(program: Command, getCtx: () => ArbContext
 				const confirmMsg = isSingle
 					? `Remove workspace ${singleName}?`
 					: `Remove ${plural(assessments.length, "workspace")}?`;
-				const shouldRemove = await confirm({ message: confirmMsg, default: false });
+				const shouldRemove = await confirm({ message: confirmMsg, default: false }, { output: process.stderr });
 				if (!shouldRemove) {
 					process.stderr.write("Aborted.\n");
 					return;
 				}
 
 				const allRemoteRepos = assessments.flatMap((a) => a.remoteRepos);
 				if (allRemoteRepos.length > 0 && !deleteRemote) {
-					deleteRemote = await confirm({ message: "Also delete remote branches?", default: false });
+					deleteRemote = await confirm(
+						{ message: "Also delete remote branches?", default: false },
+						{ output: process.stderr },
+					);
 				}
 			}
 

src/lib/integrate.ts

@@ -98,10 +98,13 @@ export async function integrate(
 			error("Not a terminal. Use --yes to skip confirmation.");
 			process.exit(1);
 		}
-		const ok = await confirm({
-			message: `${verb} ${plural(willOperate.length, "repo")}?`,
-			default: false,
-		});
+		const ok = await confirm(
+			{
+				message: `${verb} ${plural(willOperate.length, "repo")}?`,
+				default: false,
+			},
+			{ output: process.stderr },
+		);
 		if (!ok) {
 			process.stderr.write("Aborted.\n");
 			process.exit(130);

src/lib/repos.ts

@@ -37,18 +37,24 @@ export async function selectInteractive(items: string[], message: string): Promi
 	}
 
 	if (items.length === 1) {
-		const yes = await confirm({
-			message: `Only option: ${items[0]}. Include it?`,
-			default: true,
-		});
+		const yes = await confirm(
+			{
+				message: `Only option: ${items[0]}. Include it?`,
+				default: true,
+			},
+			{ output: process.stderr },
+		);
 		return yes ? items : [];
 	}
 
-	return checkbox({
-		message,
-		choices: items.map((name) => ({ name, value: name })),
-		pageSize: 20,
-	});
+	return checkbox(
+		{
+			message,
+			choices: items.map((name) => ({ name, value: name })),
+			pageSize: 20,
+		},
+		{ output: process.stderr },
+	);
 }
 
 export async function selectReposInteractive(reposDir: string): Promise<string[]> {

test/arb.bats

@@ -840,6 +840,20 @@ teardown() {
     [[ "$output" == *"does not exist"* ]]
 }
 
+@test "arb cd path output is clean when stdout is captured (shell wrapper pattern)" {
+    arb create my-feature --all-repos
+    # Simulate the shell wrapper: capture stdout via $(), which makes stdout a pipe.
+    # Verify only the workspace path appears on stdout (no UI, no hint).
+    _arb_dir="$(arb cd my-feature 2>/dev/null)"
+    [ "$_arb_dir" = "$TEST_DIR/project/my-feature" ]
+}
+
+@test "arb cd subpath output is clean when stdout is captured" {
+    arb create my-feature repo-a
+    _arb_dir="$(arb cd my-feature/repo-a 2>/dev/null)"
+    [ "$_arb_dir" = "$TEST_DIR/project/my-feature/repo-a" ]
+}
+
 # ── status ───────────────────────────────────────────────────────
 
 @test "arb status shows base branch name" {