python - Heroku - Flask - Bcrypt error -

i attempting deploy flask app on heroku , errors @ same place. gcc fails install , compile bcrypt module removed requirements.txt (it not used in app). when view requrements.txt file, there no mention of bcrypt when push heroku, still tries install it. have committed recent version of requirements.txt git. appreciated.

i able solve using custom heroku build pack:

heroku config:add buildpack_url=git://github.com/mfenniak/heroku-buildpack-python-libffi.git