Tengo un setup.cfg con

 [tool:pytest] doctest_encoding = utf-8 log_cli = 0 log_cli_level = INFO log_cli_format = %(asctime)s [%(levelname)8s] %(message)s (%(filename)s:%(lineno)s) log_cli_date_format=%Y-%m-%d %H:%M:%S

y me sale el siguiente mensaje de error

 $ pip install .[all] Processing /some/repo ERROR: Complete output from command python setup.py egg_info: ERROR: Traceback (most recent call last): File "<string>", line 1, in <module> File "/tmp/pip-req-build-599014dc/setup.py", line 72, in <module> setup(**config) File "/usr/local/lib/python3.7/site-packages/setuptools/__init__.py", line 144, in setup _install_setup_requires(attrs) File "/usr/local/lib/python3.7/site-packages/setuptools/__init__.py", line 137, in _install_setup_requires dist.parse_config_files(ignore_option_errors=True) File "/usr/local/lib/python3.7/site-packages/setuptools/dist.py", line 695, in parse_config_files self._parse_config_files(filenames=filenames) File "/usr/local/lib/python3.7/site-packages/setuptools/dist.py", line 599, in _parse_config_files val = self._try_str(parser.get(section, opt)) File "/usr/local/lib/python3.7/configparser.py", line 799, in get d) File "/usr/local/lib/python3.7/configparser.py", line 394, in before_get self._interpolate_some(parser, option, L, value, section, defaults, 1) File "/usr/local/lib/python3.7/configparser.py", line 434, in _interpolate_some option, section, rawval, var) from None configparser.InterpolationMissingOptionError: Bad value substitution: option 'log_cli_format' in section 'tool:pytest' contains an interpolation key 'asctime' which is not a valid option name. Raw value: '%(asctime)s [%(levelname)8s] %(message)s (%(filename)s:%(lineno)s)' ---------------------------------------- ERROR: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-req-build-599014dc/ ERROR: Job failed: exit code 1

cuando se ejecuta en una imagen Docker basada en python:3.7-slim en Gitlab.

Cuando elimino las dos líneas

 log_cli_format = %(asctime)s [%(levelname)8s] %(message)s (%(filename)s:%(lineno)s) log_cli_date_format=%Y-%m-%d %H:%M:%S

también funciona en el contenedor Docker que se ejecuta en Gitlab. Funciona para ambos en mi máquina (Ubuntu 18.04)

¿Por qué sucede eso y cómo lo soluciono?