Log Message:
geckodriver: update to 0.20.1. Fixes build with rust 1.24.1.

Fixes PR pkg/53263, tested by Mayuresh.

0.20.1:

Fixed

    Avoid attempting to kill Firefox process that has stopped.

    With the change to allow Firefox enough time to shut down in
    0.20.0, geckodriver started unconditionally killing the process
    to reap its exit status. This caused geckodriver to inaccurately
    report a successful Firefox shutdown as a failure.

    The regression should not have caused any functional problems, but
    the termination cause and the exit status are now reported correctly.

0.20.0:

Added

    New --jsdebugger flag to open the Browser Toolbox when Firefox
    launches. This is useful for debugging Marionette internals.

    Introduced the temporary, boolean capability
    moz:useNonSpecCompliantPointerOrigin to disable the WebDriver
    conforming behavior of calculating the Pointer Origin.

Changed

    HTTP status code for the StaleElementReference error changed
    from 400 (Bad Request) to 404 (Not Found).

    Backtraces from geckodriver no longer substitute for missing
    Marionette stacktraces.

    webdriver crate upgraded to 0.35.0.

Fixed

    The Firefox process is now given ample time to shut down, allowing
    enough time for the Firefox shutdown hang monitor to kick in.

    Firefox has an integrated background monitor that observes
    long-running threads during shutdown. These threads will be
    killed after 63 seconds in the event of a hang. To allow Firefox
    to shut down these threads on its own, geckodriver has to wait
    that time and some additional seconds.

    Grapheme clusters are now accepted as input for keyboard input
    to actions.

    Input to the value field of the keyDown and keyUp action
    primitives used to only accept single characters, which means
    geckodriver would error when a valid grapheme cluster was sent in,
    for example with the tamil nadu character U+0BA8 U+0BBF.

    Thanks to Greg Fraley for fixing this bug.

    Improved error messages for malformed capability values.