install hook fails

[José Antonio Rey]

The install hook fails due to a pip error:

2015-01-08 22:08:06 INFO unit.firefox-sync/0.install logger.go:40 Command /usr/local/sync_server/server-full/bin/python2 -c "import setuptools;__file__='/usr/local/sync_server/server-full/build/PasteScript/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /tmp/pip-nMED4x-record/install-record.txt --install-headers /usr/local/sync_server/server-full/include/site/python2.7 failed with error code 1 in /usr/local/sync_server/server-full/build/PasteScript
2015-01-08 22:08:06 INFO unit.firefox-sync/0.install logger.go:40 Storing complete log in /root/.pip/pip.log
2015-01-08 22:08:06 INFO unit.firefox-sync/0.install logger.go:40 make: *** [build] Error 1
2015-01-08 22:08:06 ERROR juju.worker.uniter uniter.go:608 hook "install" failed: exit status 2