Unable to install psycopg2-binary 2.9.1 without build prerequisites

[pomverte]

Unable to install psycopg2-binary==2.9.1

It seems to ask https://www.psycopg.org/docs/install.html#build-prerequisites

$ uname -a
Linux ip-10-1-1-44 4.19.0-16-cloud-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64 GNU/Linux
$ python3 --version
Python 3.7.3
$ pip3 --version
pip 18.1 from /usr/lib/python3/dist-packages/pip (python 3.7)

$ pip3 install psycopg2-binary==2.9.1
Collecting psycopg2-binary==2.9.1
  Downloading https://files.pythonhosted.org/packages/14/65/223a5b4146b1d5d5ab66f16ef194916a1ed9720da1f118d7bfb60b8f2bea/psycopg2-binary-2.9.1.tar.gz (380kB)
    100% |████████████████████████████████| 389kB 3.3MB/s 
    Complete output from command python setup.py egg_info:
    running egg_info
    creating pip-egg-info/psycopg2_binary.egg-info
    writing pip-egg-info/psycopg2_binary.egg-info/PKG-INFO
    writing dependency_links to pip-egg-info/psycopg2_binary.egg-info/dependency_links.txt
    writing top-level names to pip-egg-info/psycopg2_binary.egg-info/top_level.txt
    writing manifest file 'pip-egg-info/psycopg2_binary.egg-info/SOURCES.txt'
    
    Error: pg_config executable not found.
    
    pg_config is required to build psycopg2 from source.  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'.
    
    If you prefer to avoid building psycopg2 from source, please install the PyPI
    'psycopg2-binary' package instead.
    
    For further information please check the 'doc/src/install.rst' file (also at
    <https://www.psycopg.org/docs/install.html>).
    
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-h9x07b1q/psycopg2-binary/

Workaround: pip3 install psycopg2-binary==2.8.6

[dvarrazzo]

Have you upgraded pip, as specified in the documentation?