Collecting psycopg2==2.6.2 (from -r requirements.txt (line 8))
 Using cached psycopg2-2.6.2.tar.gz
 Complete output from command python setup.py egg_info:
 running egg_info
 creating pip-egg-info/psycopg2.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
 writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'
 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'.
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Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/1k/_yh_dpzn721401tdqztp_qb40000gn/T/pip-build-aBbk2v/psycopg2/