Issues installing because of missing pg_config

I am trying to install contextualise on macOS 10.14.6 and Python 3.7.

/tmp
❯ virtualenv c-ize
Using base prefix '/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7'
New python executable in /private/tmp/c-ize/bin/python3.7
Also creating executable in /private/tmp/c-ize/bin/python
Installing setuptools, pip, wheel...
done.

/tmp
❯ source c-ize/bin/activate

/tmp
c-ize ❯ pip3 freeze

/tmp
c-ize ❯ git clone https://github.com/brettkromkamp/contextualise
Cloning into 'contextualise'...
remote: Enumerating objects: 155, done.
remote: Counting objects: 100% (155/155), done.
remote: Compressing objects: 100% (108/108), done.
remote: Total 1133 (delta 101), reused 87 (delta 45), pack-reused 978
Receiving objects: 100% (1133/1133), 769.37 KiB | 9.05 MiB/s, done.
Resolving deltas: 100% (833/833), done.

/tmp
c-ize ❯ cd contextualise

/tmp/contextualise master
c-ize ❯ pip3 install -e .
Obtaining file:///private/tmp/contextualise
Collecting flask (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/9b/93/628509b8d5dc749656a9641f4caf13540e2cdec85276964ff8f43bbb1d3b/Flask-1.1.1-py2.py3-none-any.whl
Collecting flask-security (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/88/47/4908a5040120768ff4fb2465c7eeafeb9239c27d2919bd67c4ccc1b43e14/Flask_Security-3.0.0-py2.py3-none-any.whl
Collecting flask-sqlalchemy (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/1e/65/226d95466c75e34e291a76890ed0e27af2e46ab913002847856f11d4d59d/Flask_SQLAlchemy-2.4.1-py2.py3-none-any.whl
Collecting sqlalchemy (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/fc/49/82d64d705ced344ba458197dadab30cfa745f9650ee22260ac2b275d288c/SQLAlchemy-1.3.8.tar.gz
Collecting bcrypt (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/62/20/4c94f3f8dfc6b8720c8bc903ce2951ec6397ad864e3a64b4abdced014514/bcrypt-3.1.7-cp34-abi3-macosx_10_6_intel.whl
Collecting topic-db (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/91/e9/1a3068a8326f5dbe0bc0669b7ae5989e1e80c5bee2951aad32788bafdf8c/topic_db-1.0.0-py3-none-any.whl
Collecting maya (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/1d/56/789ebf410acc1491bf4078ef57a7a277b42c0b18f43e17007bfb6c1caaf3/maya-0.6.1-py2.py3-none-any.whl
Collecting mistune (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/09/ec/4b43dae793655b7d8a25f76119624350b4d65eb663459eb9603d7f1f0345/mistune-0.8.4-py2.py3-none-any.whl
Collecting python-slugify (from contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/f5/ef/c868a9ac657405f051a8a501ac5633e769c54228716b8db7f8d717977e57/python-slugify-3.0.4.tar.gz
Collecting click>=5.1 (from flask->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl
Collecting itsdangerous>=0.24 (from flask->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Collecting Jinja2>=2.10.1 (from flask->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/1d/e7/fd8b501e7a6dfe492a433deb7b9d833d39ca74916fa8bc63dd1a4947a671/Jinja2-2.10.1-py2.py3-none-any.whl
Collecting Werkzeug>=0.15 (from flask->contextualise==0.3.0)
  Downloading https://files.pythonhosted.org/packages/ce/42/3aeda98f96e85fd26180534d36570e4d18108d62ae36f87694b476b83d6f/Werkzeug-0.16.0-py2.py3-none-any.whl (327kB)
     |████████████████████████████████| 327kB 3.2MB/s
Collecting Flask-WTF>=0.13.1 (from flask-security->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/60/3a/58c629472d10539ae5167dc7c1fecfa95dd7d0b7864623931e3776438a24/Flask_WTF-0.14.2-py2.py3-none-any.whl
Collecting passlib>=1.7 (from flask-security->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/ee/a7/d6d238d927df355d4e4e000670342ca4705a72f0bf694027cf67d9bcf5af/passlib-1.7.1-py2.py3-none-any.whl
Collecting Flask-BabelEx>=0.9.3 (from flask-security->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/80/ad/cc2b0becd98050eed775ca85d6e5fa784547acff69f968183098df8a52b3/Flask-BabelEx-0.9.3.tar.gz
Collecting Flask-Principal>=0.3.3 (from flask-security->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/14/c7/2531aca6ab7baa3774fde2dfc9c9dd6d5a42576a1013a93701bfdc402fdd/Flask-Principal-0.4.0.tar.gz
Collecting Flask-Mail>=0.7.3 (from flask-security->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/05/2f/6a545452040c2556559779db87148d2a85e78a26f90326647b51dc5e81e9/Flask-Mail-0.9.1.tar.gz
Collecting Flask-Login>=0.3.0 (from flask-security->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/c1/ff/bd9a4d2d81bf0c07d9e53e8cd3d675c56553719bbefd372df69bf1b3c1e4/Flask-Login-0.4.1.tar.gz
Collecting cffi>=1.1 (from bcrypt->contextualise==0.3.0)
  Downloading https://files.pythonhosted.org/packages/f0/48/5aa4ea664eba26dd5142558d04762f5065c02220b4665b3f7eecb9bb614e/cffi-1.12.3-cp37-cp37m-macosx_10_9_x86_64.whl (169kB)
     |████████████████████████████████| 174kB 7.6MB/s
Collecting six>=1.4.1 (from bcrypt->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/73/fb/00a976f728d0d1fecfe898238ce23f502a721c0ac0ecfedb80e0d88c64e9/six-1.12.0-py2.py3-none-any.whl
Collecting typed-tree (from topic-db->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/12/15/5b406f42408bccd063c31465d111513f2ef25a992f58fdfcfb079ded12d7/typed_tree-1.0.3-py3-none-any.whl
Collecting psycopg2 (from topic-db->contextualise==0.3.0)
  Using cached https://files.pythonhosted.org/packages/5c/1c/6997288da181277a0c29bc39a5f9143ff20b8c99f2a7d059cfb55163e165/psycopg2-2.8.3.tar.gz
    ERROR: Command errored out with exit status 1:
     command: /private/tmp/c-ize/bin/python3.7 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/k_/0fg5752j3vl3b814h2qyml_00000gn/T/pip-install-k4m2p3te/psycopg2/setup.py'"'"'; __file__='"'"'/private/var/folders/k_/0fg5752j3vl3b814h2qyml_00000gn/T/pip-install-k4m2p3te/psycopg2/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base pip-egg-info
         cwd: /private/var/folders/k_/0fg5752j3vl3b814h2qyml_00000gn/T/pip-install-k4m2p3te/psycopg2/
    Complete output (23 lines):
    running egg_info
    creating pip-egg-info/psycopg2.egg-info
    writing pip-egg-info/psycopg2.egg-info/PKG-INFO
    writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
    writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
    writing manifest file 'pip-egg-info/psycopg2.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
    <http://initd.org/psycopg/docs/install.html>).

    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

/tmp/contextualise master 8s
c-ize ❯

/tmp/contextualise master
c-ize ❯ git log
commit 1f97b45ad58de358772dafd313ce04367b2fbdd7 (HEAD -> master, origin/master, origin/develop, origin/HEAD)
Author: Brett Kromkamp <[e-mail]>
Date:   Mon Sep 23 18:44:09 2019 +0200

    Updated README.rst file.

Running pip3 install psycopg2-binary and trying the above command again does not seem to resolve the issue.

[brettkromkamp]

@machawk1 Yes, I agree. And, dockerizing Contextualise (#2) becomes very attractive.

[machawk1]

@brettkromkamp That seems like a lot of overhead for a dependency. Despite this, contextualise may want to either describe how to accomplish it or provide some automated hooks in the build process.

When projects state, “Go to this other web page to install this dependency that you have to build from source”, it might tend to scare potential users away. Automating this down to the contextualise install will ensure building psycopg2 is less of a barrier.