Bad tsserverPath in the unstable/sync API client surfaces as bare "EPIPE: broken pipe, write" instead of naming the executable

Version

• typescript@7.0.2 (gitHead 2bd066d87f5bafd315be9f40889d0a60b9e58e0b),
  @typescript/typescript-linux-x64@7.0.2
• Node v22.22.0, Linux x86_64 (Fedora 43)

Repro

import { API } from "typescript/unstable/sync";

const api = new API({ tsserverPath: "/nonexistent/binary" });
api.parseConfigFile("/some/tsconfig.json");

Expected

An error identifying the executable, along the lines of the default path's
Executable not found: <path>, or the channel's own
Unexpected EOF while reading from child process (exited with code N).

Actual

Error: EPIPE: broken pipe, write
    at writeSync (node:fs:922:3)
    at SyncRpcChannel.writeAllBuf (.../dist/api/syncChannel.js:495:27)
    at SyncRpcChannel.writeTuple (.../dist/api/syncChannel.js:314:18)
    at SyncRpcChannel.requestBytesSync (.../dist/api/syncChannel.js:221:14)
    at Client.apiRequest (.../dist/api/sync/client.js:58:37)

The same EPIPE appears for any tsserverPath that is not an API server —
/bin/cat and /bin/sleep both produce it — so the message never distinguishes
"executable missing" from "executable is not a tsgo API server".

Analysis

• resolveExePath (dist/api/options.js) returns options.tsserverPath
  unchecked: return options.tsserverPath ?? getExePath();. The default branch,
  getExePath (lib/getExePath.js), does fs.existsSync(exe) and throws
  Executable not found: <path> — the explicit-path branch has no such check.
• SyncRpcChannel.writeAllBuf (dist/api/syncChannel.js) catches only
  EAGAIN/EWOULDBLOCK and rethrows everything else raw. The read side has an
  eofError() helper that reports the child's exitCode/signalCode; the write
  side has no equivalent, so a child that died before the first request produces
  the low-level errno instead.
• The spawn "error" event (ENOENT) is never observed on the child.

A check in resolveExePath mirroring getExePath's existsSync, plus an
EPIPE branch in writeAllBuf that raises the channel's eofError(), would
cover both shapes.

Comienza con resolveExePath en dist/api/options.js y compáralo con getExePath en lib/getExePath.js; después inspecciona SyncRpcChannel.writeAllBuf y eofError en dist/api/syncChannel.js. Vuelve a ejecutar el ejemplo proporcionado de sync API con /nonexistent/binary y un ejecutable que no sea un servidor; se considera terminado cuando los errores identifican el ejecutable o la salida del proceso hijo, en lugar de exponer un EPIPE sin más.