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Write your PR description
Nearly everything you're tempted to put in a PR description belongs in a Git commit message. (As a corollaryan extension, nearly everything you put in a commit message belongs in a code commentcomments too.)
You should absolutely write a PR description manually if you're looking for a non-complete review—i.e., if your code is a WIP.
Otherwise, something simple like "see commit messages for details" is good enough. On PRs with just one commit, GitHub will automatically include that one commit's message in the description; it's totally fine to leave that in the PR description.
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