---
slug: "raspberry-pi-pico-rp2040-mac-os-sonoma-copy-input-output-error"
title: "When Copying Files to Raspberry PI Pico or RP2040 on Mac OS Sonoma Results in Input/Output Error"
description: "Here is the solution for resolving Input/output errors or Error code -36 that may occur when trying to copy files to an RP2040 microcontroller board or Raspberry Pi Pico while developing on Mac OS Sonoma."
url: "https://www.ytyng.com/en/blog/raspberry-pi-pico-rp2040-mac-os-sonoma-copy-input-output-error"
publish_date: "2023-11-21T02:51:56Z"
created: "2023-11-21T02:51:56Z"
updated: "2026-02-27T02:28:22.450Z"
categories: ["Python", "Raspberry-Pi"]
keywords: ""
featured_image_url: "https://media.ytyng.com/resize/20250615/da9db4a85b794f2684642edf4fe5a3af.png.webp?width=768"
has_video: true
has_music: true
video_urls: ["https://media.ytyng.net/ytyng-blog/296/featured-video-1.mp4", "https://media.ytyng.net/ytyng-blog/296/featured-video-2.mp4", "https://media.ytyng.net/ytyng-blog/296/featured-video-3.mp4"]
music_urls: ["https://media.ytyng.net/ytyng-blog/296/featured-music-296-2.mp3", "https://media.ytyng.net/ytyng-blog/296/featured-music-296-3.mp3"]
lang: "en"
---

# When Copying Files to Raspberry PI Pico or RP2040 on Mac OS Sonoma Results in Input/Output Error

# Problem
When trying to develop on a microcontroller board equipped with a Raspberry PI Pico or RP2040 using Mac OS Sonoma, an issue arises when copying files to the RP2040. Specifically, when executing the copy command, the following error occurs:

```
cp: code.py: could not copy extended attributes to /Volumes/CIRCUITPY/code.py: Input/output error
```
This results in the file being copied as a 0-byte file (i.e., the content is not copied).

Additionally, when attempting to drag and drop files using Finder, the following error dialog appears:

```
The Finder can’t complete the operation because some data in “” can’t be read or written.
(Error code -36)
```

![Image](https://media.ytyng.com/20231120/8d15e80161bc4c3d87b1c48be6f19188.png)

# Solution
The issue can be resolved by remounting the volume in synchronous mode.

The following script can be used to remount the volume:

```shell
#!/usr/bin/env zsh

m=$(mount | grep /Volumes/CIRCUITPY | grep synchronous)

if [ ! "$m" ]; then
  devname=$(df | grep CIRCUITPY | cut -d" " -f1)
  sudo umount /Volumes/CIRCUITPY
  sudo mkdir /Volumes/CIRCUITPY
  sleep 2
  sudo mount -v -o sync -t msdos $devname /Volumes/CIRCUITPY
fi
```

# Reference Information
[OSError: [Errno 5] Input/output: macOS Sonoma is delaying writes on small filesystems · Issue #8449 · adafruit/circuitpython](https://github.com/adafruit/circuitpython/issues/8449)

# Cause
In Sonoma, when copying files, a virtual file is first created, and a page-out to the file system is triggered. If mounted asynchronously, updates to the FAT and metadata are delayed until the data is flushed, resulting in a 0-byte file. This issue occurs under the conditions of filesystems smaller than 8MB, FAT16, UF2, and Python file writes.

https://github.com/adafruit/circuitpython/issues/8449#issuecomment-1745372269

# My Solution
I created the following deployment script to address the issue.

## remount.sh

```shell
#!/usr/bin/env zsh

ret=$(mount | grep /Volumes/CIRCUITPY | grep synchronous)

if [ ! "$ret" ]; then
  devname=$(df | grep CIRCUITPY | cut -d" " -f1)
  sudo umount /Volumes/CIRCUITPY
  sudo mkdir /Volumes/CIRCUITPY
  sleep 2
  sudo mount -v -o sync -t msdos $devname /Volumes/CIRCUITPY
fi
```

## deploy.sh
```shell
#!/usr/bin/env zsh

cd $(dirname $0)

# Address the Input/output error issue when copying files on Sonoma and later
./remount.sh

files=(
  file_1.py
  file_2.py
)

for file in $files; do
  echo $file
  cp $file /Volumes/CIRCUITPY/
done

# Clean up junk files
dot_clean /Volumes/CIRCUITPY
ls -lhatr /Volumes/CIRCUITPY
```