fix(sandbox): make interactive connect resilient on stopped/resumed sandboxes#215
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…andboxes `sandbox connect` could hang on "Waiting for connection..." or fail when run against a stopped/resumed sandbox. Three independent issues: - The CLI swallowed real `attach()` failures: once the connection handshake landed, the same abort signal used to stop the premature-exit check also discarded any later `attach()` error, so failures were never surfaced. - The spinner's disposer called `ora.clear()` instead of `stop()`, leaving the render interval running and keeping the event loop (and the CLI) alive indefinitely on teardown. - When the interactive server exited early, the generic error hid the actual cause; we now include the server's stderr. - The in-sandbox server (pty-tunnel-server) trusted a leftover /tmp/vercel/interactive/config.json restored from a snapshot whenever its recorded PID happened to be alive, connecting to a dead socket. It now health-checks a reused server and removes the stale config before spawning a fresh one. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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QuiiBz
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This PR was opened by the [Changesets release](https://github.com/changesets/action) GitHub action. When you're ready to do a release, you can merge this and the packages will be published to npm automatically. If you're not ready to do a release yet, that's fine, whenever you add more changesets to main, this PR will be updated. # Releases ## sandbox@3.1.1 ### Patch Changes - Fix `sandbox connect` hanging or failing on a stopped/resumed sandbox. The interactive shell now surfaces `attach()` failures instead of swallowing them once the connection handshake lands, always stops the spinner on teardown (so a failure can no longer hang the process), and includes the in-sandbox server's stderr when the interactive server exits early. The in-sandbox `vc-interactive-server` also health-checks a reused server before trusting a leftover config file, so a stale `/tmp/vercel/interactive/config.json` restored from a snapshot no longer causes it to connect to a dead socket. ([#215](#215)) --------- Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com> Co-authored-by: Marc Codina <marc.codina@vercel.com>
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Problem
sandbox connect(and interactivesandbox exec) could hang indefinitely onWaiting for connection..., or fail in a confusing way, when run against a stopped sandbox that has to be resumed. It worked reliably against an already-running sandbox, which is why it only showed up intermittently after a stop/resume.Several independent issues combined to produce this:
Real connection errors were swallowed. Once the connection handshake landed, the abort signal that stops the "did the command exit early?" check was also used to filter errors from
attach(). So any failure that happened after the handshake (for example, the resumed session not yet exposing a route for the interactive port) was silently discarded instead of surfaced.The spinner kept the process alive. The progress spinner's teardown called
ora.clear(), which only erases the current frame but leaves its render interval running. That timer keeps Node's event loop alive, so on any early teardown the CLI would sit forever on the spinner instead of exiting.Early server exits were opaque. When the in-sandbox interactive server exited before connecting, the CLI showed a generic "may have timed out" hint with no detail.
The in-sandbox server trusted a stale config.
pty-tunnel-serverdecided whether a server was already running purely from a leftover config file and a liveness check on its recorded PID. Across a snapshot/resume that config is restored from the snapshot while the original process is gone, so a coincidentally-reused PID made it connect to a dead socket and exit.Solution
attach()through the connection-established abort filter, so genuine connection failures propagate instead of being swallowed.stop()the spinner on teardown (not justclear()), so a failure before the connection is established can no longer hang the process.pty-tunnel-serverhealth-check a server before reusing it, and remove any leftover config before spawning a new one, so a stale config restored from a snapshot can no longer cause a connection to a dead socket.Together these turn the previous silent hang into either a working connection or a fast, legible error.
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