安装命令：
pip install PyQt5==5.15.2 --config-settings --confirm-license= --verbose -i https://mirrors.aliyun.com/pypi/simple/遇到出错：
如图：
分析具体错误内容：
These bindings will be built: Qt, QtCore, QtNetwork, QtGui, QtWidgets, QtDBus, QtSql, QtXml, _QOpenGLFunctions_ES2, pylupdate, pyrcc.
Generating the Qt bindings...
_in_process.py: /tmp/pip-install-asecfkf9/pyqt5_19c1396a09f04101828420ed5f54c179/sip/QtCore/qprocess.sip: line 99: column 5: 'Q_PID' is undefined
error: subprocess-exited-with-error
× Preparing metadata (pyproject.toml) did not run successfully.
│ exit code: 1
╰─> See above for output.
note: This error originates from a subprocess, and is likely not a problem with pip.
full command: /home/pi/anaconda3/envs/py38qt5/bin/python /home/pi/anaconda3/envs/py38qt5/lib/python3.8/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py prepare_metadata_for_build_wheel /tmp/tmpvs7_f0g7
cwd: /tmp/pip-install-asecfkf9/pyqt5_19c1396a09f04101828420ed5f54c179
Preparing metadata (pyproject.toml) ... error
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.
解决办法：打开/sip/QtCore/qprocess.sip这个文件，除过30行，删除23—32之间的行：
我的解决办法是：
先用WinScp进入开发板的 /tmp目录，然后执行安装命令，立即刷新此目录， 找到最新的一个以“pip-install-*”开头的子目录，然后依次进入/pyqt5_****/sip/QtCore/子目录，找到qprocess.sip，把这个文件拖到本地，修改好后，再拖到开发板中覆盖。
如果仍然提示错误，说明你手太慢。重来一遍，手速够快的话就不报错了。
经过漫长的等待，发现PyQt5.15.2安装成功了。