fix(lifecycle): remove stdin listeners causing spurious MCP -32000 errors#255
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flightlesstux wants to merge 1 commit intomksglu:mainfrom
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fix(lifecycle): remove stdin listeners causing spurious MCP -32000 errors#255flightlesstux wants to merge 1 commit intomksglu:mainfrom
flightlesstux wants to merge 1 commit intomksglu:mainfrom
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…rors The lifecycle guard registered end/close/error listeners on process.stdin and called process.stdin.resume(). This conflicted with StdioServerTransport, which owns the same stream via readline. Transient pipe events triggered gracefulShutdown() → process.exit(0), so the MCP client logged "MCP error -32000: Connection closed" multiple times per hour during normal sessions. Remove the stdin-based shutdown path entirely. ppid polling every 30s plus SIGTERM/SIGINT/SIGHUP handlers still guarantee the orphan protection added in mksglu#103. Update tests/lifecycle.test.ts so the integration test asserts the new contract: stdin close must NOT shut the guard down. The previous positive assertion is what made PR mksglu#237 fail CI on Ubuntu/macOS. Supersedes mksglu#237. Closes mksglu#236. Co-authored-by: ponythewhite <ponythewhite@users.noreply.github.com> Co-authored-by: Ercan Ermis <eposta@ercanermis.com>
This was referenced Apr 12, 2026
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Summary
process.stdin.resume()and theend/close/errorlisteners fromsrc/lifecycle.ts(the same diff as PR fix: remove stdin listeners from lifecycle guard to prevent MCP -32000 errors #237).tests/lifecycle.test.tsso the integration test asserts the new contract — stdin close must NOT trigger the lifecycle guard.Why
The lifecycle guard and the MCP stdio transport both own
process.stdin. Any transient pipe event firedonStdinClose→gracefulShutdown()→process.exit(0)immediately, tearing in-flight JSON-RPC responses mid-flight and producingMCP error -32000: Connection closed.ppidpolling every 30s plusSIGTERM/SIGINT/SIGHUPare enough to preserve the orphan protection from #103 without these false positives.What changed
src/lifecycle.ts— stdin listeners +resume()removed; matchingremoveListenercalls removed from the cleanup closure; JSDoc updated (both the file header and theLifecycleGuardOptions.onShutdownfield comment).tests/lifecycle.test.ts— positive test (child exits when stdin is closed) replaced with a negative one (child does NOT exit when stdin is closed (#236)). All other unit tests and the SIGTERM integration test are untouched.Why #237 is superseded
PR #237 by @ponythewhite carried the exact production-code diff but did not update the integration test, which still asserted the old contract (
exit code === 42on stdin close). CI went red on Ubuntu + macOS (Windows skips the integration block for unrelated POSIX-signal reasons). The author has been inactive for 6+ days. This PR keeps their production change verbatim and adds the test update so CI is green.Test plan
bunx vitest run tests/lifecycle.test.ts— 7 tests pass locally (5 unit + 2 integration: negative stdin, SIGTERM).vitest run— hook/session tests already fail on pristineupstream/main(pre-existing, unrelated to this fix); no new regressions introduced.bun run build && bun run bundle, spawned with stdio piped, stdin closed mid-session. The lifecycle guard no longer callsprocess.exit(0)— the server now winds down viaStdioServerTransport's normal EOF handling (clean exit, no-32000framing corruption).Credit
Co-authored with @ponythewhite whose PR #237 carried the original diff.
Closes #236