Flow version: 0.337.0 (src/commands/commandConnect.ml, src/hack_forked/utils/sys/daemon.ml and src/monitor/ are unchanged on main at 4fd0ec1)

Expected behavior

On Windows, flow check with its output piped returns once the check exits, so flow check | cat ends after No errors!.

Actual behavior

flow check starts a server when none runs over the root, prints No errors! and exits 0, but the server's processes — the monitor, its file watcher and the server master — hold the pipe the check wrote to, so whatever reads its output to the end waits until flow stop: flow check | cat, or a CI step that captures the output.

In Git Bash on Windows 11 (10.0.26300), with the gist's three files:

npm install
npx flow check | cat    # prints "No errors!" and does not return
npx flow stop           # from another shell: the first one returns

A run that timestamps the piped output and lists Flow's processes 20 s after the check exited (paths shortened):

01:44:30.122 | No errors!
01:44:30.135 | the check exited 0 at 01:44:30.027
01:44:51.164 Flow processes 20 s after the check exited:
  pid 36660, parent 45448: flow.exe "monitor for …\new-project"
  pid 60928, parent 36660: flow.exe "file watching process for server 36660"
  pid 56448, parent 36660: flow.exe "server master process watching …\new-project"
01:44:51.762 the pipe is still open; stopping the server with flow stop
01:44:51.940 the pipe closed

• Link to Try-Flow or Github repo: https://gist.github.com/YevheniiKotyrlo/4de9ff876af102310c71e0beae6897de