Rollback a Git merge

Question

develop branch
--> dashboard (working branch)

I use git merge --no-ff develop to merge any upstream changes into dashboard

Answer 1

git revert -m 1 88113a64a21bf8a51409ee2a1321442fd08db705

But may have unexpected side-effects. See --mainline parent-number option in git-scm.com/docs/git-revert

Perhaps a brute but effective way would be to check out the left parent of that commit, make a copy of all the files, checkout HEAD again, and replace all the contents with the old files. Then git will tell you what is being rolled back and you create your own revert commit :) !