fix(mcp): fall back to tmpdir socket on filesystems without AF_UNIX support#998
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zengwenliang416 wants to merge 1 commit into
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fix(mcp): fall back to tmpdir socket on filesystems without AF_UNIX support#998zengwenliang416 wants to merge 1 commit into
zengwenliang416 wants to merge 1 commit into
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…upport (colbymchenry#997) ExFAT, NTFS-3G, and some FUSE-backed volumes do not support Unix domain sockets — `listen()` fails with ENOTSUP. `getDaemonSocketPath` already had a tmpdir fallback for long paths; this extends it to also probe socket support via a short-lived child process, cached per device. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
Fixes #997.
getDaemonSocketPath()now probes whether the target directory supports Unix domain sockets before returning an in-project path. On filesystems that don't support AF_UNIX (ExFAT, NTFS-3G, some FUSE mounts), it transparently falls back to theos.tmpdir()hash-based socket — the same path already used for the long-path case.Problem
When a project lives on an ExFAT-formatted external volume (common on macOS for USB drives), the daemon fails to start:
The existing tmpdir fallback only triggered for paths exceeding 100 characters. Short paths on unsupported filesystems had no fallback.
Approach
canSocketInDir(dir)todaemon-paths.tsthat spawns a short-lived child process (execFileSync) to attempt binding a Unix socket in the target directoryfs.statSync().dev) so the probe runs at most once per mounted filesystem per process lifetimegetDaemonSocketPath()alongside the existing length checkgetDaemonSocketPath(), so they automatically agree on the socket path — no changes needed indaemon.tsorindex.tsChanges
src/mcp/daemon-paths.ts: AddedcanSocketInDir(),clearSocketSupportCache()(test helper), updatedgetDaemonSocketPath()guard__tests__/daemon-socket-probe.test.ts: New test file covering probe behavior and cache semanticsTest plan
npm run build— compiles cleanlycanSocketInDirreturns true on tmpdir, caches results, handles nonexistent dirsdaemon-bind-failure.test.tsstill passes (no regression)proxy-connect.test.tsanddaemon-registry.test.tsstill passgetDaemonSocketPath('/Volumes/exfat-drive/project')returns tmpdir path; local APFS projects still get in-project path