Often changelogs are generated from the patch branch and then
cherry-picked into the `CHANGELOG.md` file in `master` for
better access and readability. This is problematic though as
`conventional-changelog` (the tool we use for generating the
changelog), will duplicate commits when a future changelog
is generated from `master` then (i.e. for a new minor release).
This happens because conventional-changelog always generates the
changelog from the latest tag in a given branch to `HEAD`. The
tag in the patch branch does not correspond to any SHA in `master`
so the intersection of commits is not automatically omitted.
We work around this naively (until we have a better tool provided
by dev-infra), by deduping commits that are already part of the
changelog. This has proven to work as expected in the components
repo.
PR Close#37956