Dear devs

I'm working on !8750, which has some knock-on changes that are needed on the Haddock repo.   So
Periodically I need to rebase on master.

Question: what is the Blessed Sequence of Commands that I should use to push the right changes to haddock?  I think it is something like:

  1. In the main GHC repo, on branch wip/T21623
    1. git fetch
    2. git rebase origin/master
  2. In utils/haddock,
    1. identify the set of patches P1..Pn between the trunk and my haddock tip, the changes that I need to haddock.
    2. Somehow check out the haddock commit K that corresponds to origin/master
    3. Apply P1..Pn on top of K
    4. Force-push to origin/wip/spj-T21623
  3. Move to the main GHC repo
    1. git add utils/haddock
    2. Create a patch for that change
    3. Push to main repo

But I am not sure how to do step 2.2, nor what is an efficient way to do 2.3.

I would welcome very precise instructions.  Thank you!

Simon