GUIDELINE

Contributions guideline:

Keep the code simple
Don't add extra dependency: dependencies have costs that is better to avoid.
compatibility: keep the code compatible with previous versions of GHC, and base.
Don't drop older SSL / TLS features (even if insecure) without proper discussion.
Limit the change of API if necessary. it's usually better to create new API than change current one.
Notable exception to previous rule: security fix have priority to other considerations.

MAINTAINERS

Don't commit code directly to master, apart from targeted fixes (e.g. documentation improvements, build scripts, etc).
PRs: make sure they pass compilations and runtime tests before merging
Let someone else merge your own PR, or give other maintainers a chance to review
Separate meaningful code from syntax changes
Prefer rebased code when merging. A clean history is a readable history.
Merge with a merge point to keep the action of merging visible instead of fast-forward. it allows to easily revert merge point when necessary and easier reading of histor.