Function dev_url_port 

pub fn dev_url_port<'a>(
    env_vars: impl Iterator<Item = (&'a str, &'a str)>,
) -> Result<Option<u16>>

The port an adb reverse must forward, read from the WATERUI_DEV_URL entry of a launch environment. None when no dev-server handoff is present.

Errors

Returns an error when the variable is set but is not a URL — a malformed handoff is a bug to report, not a state to launch in.