Homepage: https://direnv.net
Things that are hard to change after the fact.
Naming .envrc and not .env.sh or .direnv.sh. Just a taste thing.
Not using a [global] section in the TOML config.
Stuffing too many things in the stdlib. Most direnv releases are just stdlib changes. A better solution would be to create a plugin ecosystem for stdlib functions (not too later for that!).
Not writing a comprehensive test suite. This makes changes much harder to accept.