Installing psycopg2 into virtualenv when PostgreSQL is not installed on development system

Is it possible to install psycopg2 into a virtualenv when PostgreSQL isn't installed on my development system—MacBook Pro with OS X 10.6?

When I run pip install psycopg2 from within my virtualenv, I received the error shown below.

I'm trying to connect to a legacy database on a server using Django, and I'd prefer not to install PostgreSQL on my development system if possible.

Why not install PostgreSQL?

I received an error when installing PostgreSQL using homebrew. I have Xcode4—and only Xcode4—installed on my MacBook Pro and am thinking it's related to missing gcc 4.0. However, this is a problem for another StackOverflow question.

Update 8:37 AM on April 12, 2011: I'd still like to know if this is possible without installing PostgreSQL on my MacBook Pro. However, I ran brew update and forced a reinstallation of ossp-uuid with brew install --force ossp-uuid and now brew install postgresql works. With PostgreSQL successfully installed, I was able to pip install psycopg2 from within my virtualenv.

Error from pip install psycopg2

$ pip install psycopg2
Downloading/unpacking psycopg2
  Running setup.py egg_info for package psycopg2

    Error: pg_config executable not found.

    Please add the directory containing pg_config to the PATH
    or specify the full executable path with the option:

        python setup.py build_ext --pg-config /path/to/pg_config build ...

    or with the pg_config option in 'setup.cfg'.
    Complete output from command python setup.py egg_info:
    running egg_info

writing pip-egg-info/psycopg2.egg-info/PKG-INFO
writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
warning: manifest_maker: standard file '-c' not found

Error: pg_config executable not found.

Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:

    python setup.py build_ext --pg-config /path/to/pg_config build ...

or with the pg_config option in 'setup.cfg'.

----------------------------------------
Command python setup.py egg_info failed with error code 1
Storing complete log in /Users/matthew/.pip/pip.log

Preliminary Research

Below are the articles I read as preliminary research:

• Installing psycopg2 to use Django with PostgreSQL on OS X
• Installing psycopg2 on OS X
• Using psycopg2 with virtualenv on Ubuntu JauntyLucid
• Postgres, psycopg2, virtualenv install hints

Solution 1:

apt-get install libpq-dev

helped me on debian squeeze

Solution 2:

psycopg depends on pg_config command, and if you don't have it, you can't install psycopg.

If system installation is a problem to you, why don't you try compiling PostgreSQL and including generated bin files in your $PATH? Like:

export PATH=/path/to/compiled/postgresql/bin:"$PATH"
pip install psycopg2

Solution 3:

brew install postgresql

export LDFLAGS="-L/usr/local/opt/openssl/lib"

export CPPFLAGS="-I/usr/local/opt/openssl/include"

pip3 install psycopg2