I'm attempting to install psycopg2 into a Python virtualenv with Ansible's pip module, but I need to prepend an entry to PATH for it to build correctly (it needs to know the path to the directory containing pg_config). I see that I can pass environment to the pip module, but I'm unsure of how to prepend rather than overwrite PATH.
Here I'm attempting to prepend the path with the necessary directory, but it overwrites the virtualenv PATH and fails:
- pip:
name: psycopg2
virtualenv: /path/to/my/venv
environment:
PATH: /usr/pgsql-9.3/bin:$PATH