mpremote mount succeeds but mounted filesystem requests time out on Tulip CC

[bobbijvoet]

Hi! Loving your products! But running into this issue:

mpremote mount reports success on my Tulip CC, but any access to the mounted
/remote filesystem times out. This happens with an arbitrary local folder, so
it is not specific to my app.

Environment

• Hardware: Tulip CC

• USB serial device: /dev/cu.wchusbserial2120

• Firmware banner:

  MicroPython 82e69df-dirty on 2026-07-13; TulipCC with ESP32S3
  

• Host: macOS

• mpremote: 1.28.0

• Connection: CH340/CH341 USB serial

Reproduction

In a normal macOS terminal:

.venv/bin/mpremote resume mount <local-directory>

mpremote reports a successful mount:

Local directory <local-directory> is mounted at /remote
Connected to MicroPython at /dev/cu.wchusbserial2120
Use Ctrl-] or Ctrl-x to exit this shell
>
MicroPython 82e69df-dirty on 2026-07-13; TulipCC with ESP32S3
Type "help()" for more information.
>>>

Then, at the Tulip REPL:

ls

Actual result

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "upysh.py", line 7, in **repr**
  File "upysh.py", line 11, in **call**
  File "<stdin>", line 251, in ilistdir
  File "<stdin>", line 44, in rs8
  File "<stdin>", line 23, in rinto
  File "<stdin>", line 15, in poll_in
Exception: timeout waiting for remote

The same failure occurs for a direct os.stat() of an existing file in the
mounted directory.

Expected result

ls should list the host directory mounted at /remote, and imports and file
access from that mount should work.

Notes

• I include resume, as recommended for Tulip.
• fs and repl work over the same USB serial connection.
• The failure occurs before launching my application, so it does not appear
  related to package layout or app code.
• After the timeout, mpremote reset cannot recover the device because it
  cannot enter raw REPL while the stale mount is active; a physical reboot is
  required.