树莓派4安装OpenCV-python失败求助：编译wheel及skbuild报错

问题描述 #

在Visual Studio Code中操作树莓派4，执行命令pip install opencv-python等待40分钟后出现报错：

FileNotFoundError: [Errno 2] No such file or directory: '_skbuild/linux-armv7l-3.9/cmake-install/python/cv2/config-3.py'
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for opencv-python
Failed to build opencv-python
ERROR: Could not build wheels for opencv-python, which is required to install pyproject.toml-based projects

已尝试升级pip后重新安装，问题未解决。当前使用Python版本为3.9.2。

补充：执行命令pip3 install --no-use-pep517 opencv-python时出现新报错：

error: subprocess-exited-with-error

× python setup.py egg_info did not run successfully.
│ exit code: 1
╰─> [6 lines of output]
Traceback (most recent call last):
File "", line 2, in
File "", line 34, in
File "/tmp/pip-install-zwr61c7o/opencv-python_1867909748974f69a8333e238206f9df/setup.py", line 10, in
import skbuild
ModuleNotFoundError: No module named 'skbuild'
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

解决步骤 #

1. 安装缺失的构建依赖 #

针对skbuild缺失的问题，先安装系统和Python依赖：

sudo apt-get update && sudo apt-get install -y build-essential cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
pip install scikit-build setuptools wheel

2. 使用系统预编译包安装（推荐） #

树莓派上编译OpenCV耗时极长，直接用系统包管理器安装预编译版本，速度快且稳定：

sudo apt-get install -y python3-opencv

安装完成后，在Python中验证：

import cv2
print(cv2.__version__)

3. 指定兼容版本通过pip安装 #

如果需要特定版本的OpenCV，尝试指定与Python3.9兼容的版本（该版本提供了armv7l预编译轮子）：

pip install opencv-python==4.5.5.62

4. 清理缓存后重试 #

若之前的编译缓存导致异常，清理后重新安装：

pip cache purge
pip install opencv-python --no-cache-dir

内容的提问来源于stack exchange，提问作者Ramin Moradi