ERROR: invocation failed, logfile: /home/adnan/terry-test/cryptography/.tox/log/tox-0.log
ERROR: actionid=tox
msg=packaging
cmdargs=['/usr/bin/python', local('/home/adnan/terry-test/cryptography/setup.py'), 'sdist', '--formats=zip', '-
-dist-dir', local('/home/adnan/terry-test/cryptography/.tox/dist')]
env=None
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libffi' found