Command not found, when it's in a directory on the path

I have the following environment variable set (trying for a 12-factor app approach):

• PATH="/home/hope/env/bin:$PATH"

/home/hope/env/bin is the bin directory of a virtualenv, it has gunicorn and python in it, among other things. But running commands under this directory results in some funny behavior, namely:

• python works, and sys.executable returns "/home/hope/env/bin/python" (which python says this too.)
• gunicorn doesn't work, despite which gunicorn returning "/home/hope/env/bin/gunicorn".

Obviously to serve pages from this Django app, I need to be able to find gunicorn. I feel like I'm missing something basic, any ideas?

Edit: duh, here's supervisor's output: BACKOFF can't find command 'gunicorn'. Both python and gunicorn are 755 to the same user/group.