Heroku can't find pip (very weird)

When I click on the wizard, this happened:

Counting objects: 1, done.
Writing objects: 100% (1/1), 186 bytes, done.
Total 1 (delta 0), reused 0 (delta 0)

-----> Fetching custom git buildpack... done
-----> Python app detected
-----> Preparing Python runtime (python-2.7.3)
-----> Installing Distribute (0.6.35)
-----> Installing Pip (1.3.1)
-----> Installing dependencies using Pip (1.3.1)
/tmp/buildpack_12iaablbmqzbb/bin/compile: line 164: /app/.heroku/python/bin/pip: No such file or directory
 !     Heroku push rejected, failed to compile Python app

To git@heroku.com:xxxxxxxxxx.git
 ! [remote rejected] master -> master (pre-receive hook declined)

To be clear, I pointed out the assembly because heroku incorrectly detected my python application as a ruby ​​application due to the existence of the Gemfile.

This is the configuration I pulled from heroku config

BUILDPACK_URL: https://github.com/heroku/heroku-buildpack-python

But this will not compile my application, how can I solve this?

Thank.