# list all commits in `master` not present in `pre-prod`
git log --no-merges master ^pre-prod
# for a nicer one-line-per-commit format use this
git --no-pager log --pretty=format:"%h%x09%an%x09%ad%x09%s" --no-merges master ^pre-prod
This will give you a list of Authors to involve in the merge if there are conflicts
# list all conflicting files without performing a merge (when mergin master into pre-prod)
git checkout pre-prod; git merge --no-commit --no-ff master | grep "^CONFLICT"; git merge --abort
This will give you the list of conflicting files involved in the merge without performing the merge