From 538b78baa9099972efad283f7b901e2085bd3391 Mon Sep 17 00:00:00 2001
From: Burak Yigit Kaya <byk@sentry.io>
Date: Thu, 23 Apr 2026 13:48:08 +0000
Subject: [PATCH] fix(init): add force-exit safety net for Bun fresh+readline
 hang
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After "Sentry SDK installed successfully!", `sentry init` still
hangs until a keypress despite #802/#824/#825/#831. Root cause: a
Bun 1.3.11 libuv refcount bug. Opening our fresh /dev/tty
ReadStream (the `curl | bash` TTY-delivery workaround) combined
with clack's `readline.createInterface(process.stdin)` leaks a
libuv handle that NO userland cleanup releases. Verified by a
systematic matrix test — process.stdin.{pause,destroy,close},
rl.close(), removeAllListeners, and every combination of the
above all leave the event loop ref'd.

`process.stdin.unref()` is `undefined` on Bun 1.3.11 (we can't
use Node's canonical "let the process exit" escape hatch).

The four prior PRs each fixed a legit contributing cause and
should stay — #802 and #824 release our own ReadStream, #825
releases keep-alive sockets, #831 transitions stream state to
paused. But none address the Bun bug because it's not a userland
issue.

Fix: restore PR #782's force-exit, wrapped in
`setTimeout(..., 100).unref()` so the timer itself doesn't hold
the loop. Happy path (loop drains naturally — future Bun fixes,
non-TTY flows, `--yes` with no prompts): timer never fires,
process exits normally. Bun-bug path: timer fires after 100ms
grace — imperceptible to the user, enough for Sentry telemetry +
stdio flushes to complete first.

Gated on `NODE_ENV !== 'test'` so `bun test` (which sets
NODE_ENV=test automatically) doesn't accumulate unref'd timers
that would terminate the test runner mid-suite.

Manually verified: the production repro (script -q -c "bun …"
/dev/null with a real /dev/tty) hangs 7s without this fix, exits
in 286ms with it.
---
 src/commands/init.ts | 39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/commands/init.ts b/src/commands/init.ts
index bd43f5a02..bc32b59e8 100644
--- a/src/commands/init.ts
+++ b/src/commands/init.ts
@@ -270,8 +270,7 @@ export const initCommand = buildCommand<
     }
 
     // 6. Run the wizard. It owns the temporary `/dev/tty` forwarding used
-    //    for `curl | bash` flows and tears it down on every exit path, so
-    //    init can return naturally once its own refs are released.
+    //    for `curl | bash` flows and tears it down on every exit path.
     await runWizard({
       directory: targetDir,
       yes: flags.yes,
@@ -281,5 +280,41 @@ export const initCommand = buildCommand<
       org: explicitOrg,
       project: explicitProject,
     });
+
+    // 7. Force-exit safety net for a Bun libuv refcount bug.
+    //
+    // On Bun 1.3.11, combining our fresh `/dev/tty` ReadStream (needed for
+    // the `curl | bash` TTY-delivery workaround in stdin-reopen.ts) with
+    // clack's internal `readline.createInterface(process.stdin)` leaks a
+    // libuv handle that NO userland cleanup releases:
+    // `process.stdin.{pause,destroy,close}`, `rl.close()`,
+    // `removeAllListeners`, and every combination of the above all leave
+    // the event loop ref'd. `process.stdin.unref` is `undefined` on Bun.
+    // The wizard prints "Sentry SDK installed successfully!" and the
+    // process then hangs until the user presses a key (which wakes libuv).
+    //
+    // PRs #802, #824, #825, and #831 each fixed a legit contributing cause
+    // (ReadStream ref, `using` teardown, MastraClient sockets, stream
+    // flowing state) and should all stay — but none address the underlying
+    // Bun refcount bug because that's not a userland issue. PR #782's
+    // original `process.exit(0)` workaround was removed on the assumption
+    // that natural drain would work after the other fixes; it doesn't.
+    //
+    // Safety net: schedule a force-exit with `.unref()` so the timer
+    // itself doesn't hold the loop. If the loop drains naturally (future
+    // Bun versions, non-TTY flows, `--yes` with no prompts), the timer
+    // never fires and the process exits normally. If the Bun bug bites,
+    // the timer fires after a 100ms grace period — imperceptible to
+    // the user and enough for Sentry telemetry + stdio flushes to
+    // complete first.
+    //
+    // Skipped under `bun test` (which sets `NODE_ENV=test`) because the
+    // test runner calls `initCommand.func` directly; an unref'd timer
+    // would still fire and terminate the runner mid-suite.
+    if (process.env.NODE_ENV !== "test") {
+      setTimeout(() => {
+        process.exit(process.exitCode ?? 0);
+      }, 100).unref();
+    }
   },
 });