SQL config error on Mac OSX installation

With Python3 and pip3 on Mac OSX, there's a sql config error

$ sudo pip3 install -U https://github.com/clips/pattern/archive/development.zip

Collecting https://github.com/clips/pattern/archive/development.zip
  Downloading https://github.com/clips/pattern/archive/development.zip (24.8MB)
    100% |████████████████████████████████| 24.8MB 40kB/s 
Collecting future (from Pattern==2.6)
  Downloading future-0.16.0.tar.gz (824kB)
    100% |████████████████████████████████| 829kB 850kB/s 
Collecting backports.csv (from Pattern==2.6)
  Downloading backports.csv-1.0.5-py2.py3-none-any.whl
Collecting mysqlclient (from Pattern==2.6)
  Downloading mysqlclient-1.3.12.tar.gz (89kB)
    100% |████████████████████████████████| 92kB 2.5MB/s 
    Complete output from command python setup.py egg_info:
    /bin/sh: mysql_config: command not found
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/tmp/pip-build-c2voibrz/mysqlclient/setup.py", line 17, in <module>
        metadata, options = get_config()
      File "/private/tmp/pip-build-c2voibrz/mysqlclient/setup_posix.py", line 44, in get_config
        libs = mysql_config("libs_r")
      File "/private/tmp/pip-build-c2voibrz/mysqlclient/setup_posix.py", line 26, in mysql_config
        raise EnvironmentError("%s not found" % (mysql_config.path,))
    OSError: mysql_config not found
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/tmp/pip-build-c2voibrz/mysqlclient/

Start by reproducing the documented Python 3 and pip3 installation command on macOS and inspect the mysqlclient dependency failure showing that mysql_config is missing. The issue provides no target file, test, or agreed resolution, so completion criteria are not defined in the report.