To check which APT dependency package of gnome-core has firefox-esr as a dependency, you can use the following steps in a terminal on a Debian-based system (e.g., Ubuntu):

Method 1: Using apt-cache

Run the following command to list all dependencies of gnome-core and filter for firefox-esr:

apt-cache depends gnome-core | grep firefox-esr

This will show you if firefox-esr is directly or indirectly a dependency of gnome-core.

Method 2: Using apt-rdepends (if installed)

If you have the apt-rdepends tool installed, you can use it to recursively check dependencies:

apt-rdepends gnome-core | grep firefox-esr

If apt-rdepends is not installed, you can install it with:

sudo apt install apt-rdepends

Method 3: Manual Inspection

If the above methods don't work, you can manually inspect the dependencies of gnome-core and its sub-packages:

1. List all dependencies of gnome-core:

   bash

   Copy

   apt-cache depends gnome-core

2. For each dependency, check if it depends on firefox-esr:

   bash

   Copy

   apt-cache depends <package-name> | grep firefox-esr

Method 4: Using debsums or dpkg

If you want to check installed packages, you can use:

dpkg -l | grep gnome-core

Then inspect the dependencies of the installed version.

Expected Output

If firefox-esr is a dependency of any package in the gnome-core dependency tree, the command will return the package name(s) that depend on it. If no output is returned, firefox-esr is not a dependency of gnome-core or its sub-packages.