Adrian Klaver

Thanks for looking at it. I am still groping my way through distutils to see if there is a solution.

I am afraid the previous idea would not work for the case:

sudo python setup.py install

As soon as sudo is invoked the PATH gets restricted.
My personal short t...

Well that is not going to work. The various steps seem to take place as discrete actions with no state saved. I thought of using the pg_config setting in setup....

Seems this is where the problem arises:

def finalize_options(self):

    """Complete the build system configuation."""
    build_ext.finalize_options(self)

   ...

Have been doing some digging around.
What I found so far.
In the sudoers file there in a setting env_reset that restricts the PATH when using sudo. There are ot...

The PATH for root also contains the pg_config directory. As I said in the original problem report, when I run build/install entirely as root there is no problem...

os-linux
There seems to an issue using sudo when installing from source or pip. setup.py complains that pg_config cannot be found on the path.
Checking the PATH...

Works for me. Not sure I follow the InterfaceError/TypeError debate though. Per my example from 2.4.2 above, psycopg2 used to raise TypeError for invalid parame...

Patched and it works after a fashion. In particular the error message is confusing:
InterfaceError: you cannot specify keyword arguments (conection_factory) tog...

How can it be forbidden? When:
_connect(dsn, connection_factory=connection_factory, async=async)
I see both a dsn and a connection_factory argument.