Fix Windows EPIPE errors on stdin during process cleanup

Add error handler on stdin stream to suppress EPIPE errors that occur
when the child process exits before we finish writing to it. This is
expected during cleanup when killing processes on Windows.

Author: Taras Mankovski

process/src/exec/win32.ts

@@ -123,6 +123,15 @@ export const createWin32Process: CreateOSProcess = (command, options) => {
       return status;
     }
 
+    // Suppress EPIPE errors on stdin - these occur on Windows when the child
+    // process exits before we finish writing to it. This is expected during
+    // cleanup when we're killing the process.
+    childProcess.stdin.on("error", (err: Error & { code?: string }) => {
+      if (err.code !== "EPIPE") {
+        throw err;
+      }
+    });
+
     try {
       yield* provide({
         pid: pid as number,