Not sure how many people here build from source, but I found that at some point in the last month or so it started to fail completely with this error:
Installed /usr/local/lib/python2.7/dist-packages/Flask_WTF-0.14.2-py2.7.egg
error: The 'Flask' distribution was not found and is required by flask-wtf, flask-testing, flask-script, flask-cache
This was fixed by adding
'flask==0.12.1',
to install_requires in setup.py.
Has anyone else encountered this?