While updating ERPNext, Pillow compilation error

[rmehta]

New python dependency - Pillow. If you get error during update, see this post

The new dependency Pillow is used to generate image thumbnails for shopping cart. Command “/home/USER/frappe-bench/env/bin/python -c “import setuptools, tokenize;file=‘/tmp/pip-build-ZOfqQL/Pillow/setup.py’;exec(compile(getattr(tokenize, ‘open’, open)(file).read().replace(‘\r\n’, ‘\n’), file, ‘exec’))” install --record /tmp/pip-NAQ3qY-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/sam/frappe-bench/env/include/site/python2.7/Pillow” failed with …