Hi! We'd like to propose a new functionality for dnf: When a user tries to install a package XYZ and dnf doesn't find it, dnf would recommend them alternative packages. These offered packages would advertise that they are an alternative for XYZ using a specially formatted Provides tag.

For example, packages `python2-requests` and `python3-requests` would both have the following tag:

Provides: alternative-for(python-requests) = %{version}-%{release}

(Possibly via the already existing and widespread %python_provide macro in the Python case.)

And when the user would try to install `python-requests`, dnf would look for packages with the relevant Provides tag and display them:

# dnf install python-requests       * There are following alternatives to this package: python2-requests python3-requests     No match for argument: python-requests     Error: Unable to find a match

This would be very similar to an already existing functionality that searches for lowercase package names:

# dnf install python3-REQUESTS       * Maybe you meant: python3-requests     No match for argument: python3-REQUESTS     Error: Unable to find a match

(That functionality is broken in some versions—RHBZ#1628514—so you might not see this result at the moment.)

What are your thoughts?

One possible addition would be to include a parameter for weight in the Provides tag, so that python3-requests could be listed as the preferred option before python2-requests.

All the best, Tomas Orsava