In the win7 system, under the command terminal, the two methods of installing pycallgraph report the exception of subprocess exited with error
Solution: downgrade setuptools
1. First check the current version of setuptools.
pip show setuptools
2. The version of setuptools has been downgraded. Here, I downgraded it to 57.5.0
pip install --upgrade setuptools==57.5.0
3. Try installing pycallgraph again
pip install pycallgraph