Comment 2 for bug 1960749

This is a feature, not a bug.

Docker images are not intended for interactive use, as such use minimized images, and dpkg is configured to not install any documentation.

A script 'unminize' is provided to convert a minimized image into a full one.

root@3a7cdb2c772b:/# cat /etc/dpkg/dpkg.cfg.d/excludes
# Drop all man pages
path-exclude=/usr/share/man/*

# Drop all translations
path-exclude=/usr/share/locale/*/LC_MESSAGES/*.mo

# Drop all documentation ...
path-exclude=/usr/share/doc/*

# ... except copyright files ...
path-include=/usr/share/doc/*/copyright

# ... and Debian changelogs for native & non-native packages
path-include=/usr/share/doc/*/changelog.*