I got the following error when installing matplotlib:

sudo python -mpip install -U matplotlib

Command "/usr/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-install-t_g0M1/subprocess32/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-record-YcuLqR/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /tmp/pip-install-t_g0M1/subprocess32/

I fixed it by installing python-dev:
sudo apt-get install python-dev

ref:

https://github.com/google/python-subprocess32/issues/38