SDIO issue with readyonly true

[djecken]

CircuitPython version and board name

Adafruit CircuitPython 10.0.3 on 2025-10-17; Adafruit Feather RP2040 Prop-Maker with rp2040

Code/REPL

storage.mount(vfs, "/sd", readonly=True)

Behavior

OSError: [Errno 2] No such file/directory:

Description

hey folks, I came across this bug while working on this project: https://learn.adafruit.com/color-sensing-music-player

The code uses storage.mount(vfs, "/sd", readonly=True) that allows writing files to the SD card while in USB host mode. After adding/removing a few files from the SD card, the circuitpy becomes unstable and puts the board in a weird state where it won't mount. Also, files on the SD card get cached and corrupted, making it difficult to delete files. I'm running Mac OS Tahoe 26.2 but issue is also prevalent on Windows.

Additional information

No response