Bungie released Harbringer, the activity that will let players farm random rolls on Hawkmoon and get the catalyst for the weapon which makes it exceptionally powerful.
Harbringer is technically a new activity since it didn't exist in Destiny 2 before but it's also a vigorous exercise in recycling as Guardians will walk the paths they travelled several times over by now in order to acquire the weapon's random rolls and catalyst.
You will be facing Taken enemies all over the place and this is another one of those instances where devs are pretending that bullet sponges with one-shot capabilities are fun and engaging content. Therefore, it would be very wise to bring a fireteam with you instead of doing the activity solo.
Furthermore, Harbringer is a 1,270 Light activity so make sure you have farmed up the otherwise arbitrary number before entering. Enemies you will face have Arc, Solar and Void shields so make sure the damage types are varied enough as they appear to have increased resistance to elements not matching their shields.
If that wasn't enough, there are Unstoppable champions in the final encounter so those mods will be necessary as well. Overall, the activity will likely require some cheesing but the rewards are pretty chunky since Hawkmoon will gain one additional bullet as well as better range, handling and reload speed based on the number of Paracausal Charge stacks.
Currently, it appears that you can only run Harbringer once a week on each character so at least we are prevented from rushing into misery repeatedly, to a certain degree.