function pip_sync --description "Make a virtualenv dependencies look like requirements.txt"

    # If there isn't a virtualenv already, create one
    if test -z "$VIRTUAL_ENV"
        venv
    end

    # If there are no `requirements.txt` files, run my `pip compile`
    # script to create a set of version pins.
    if not test -e requirements.txt; and not test -e dev_requirements.txt; or contains -- --compile $argv;
        or contains -- --upgrade $argv
        pip_compile $argv

        echo ""
    end

    # Actually run the `uv pip sync` command.
    run_pip_sync $argv
end