> cat geckodriver.log
1523564553980   geckodriver     INFO    geckodriver 0.20.1
1523564553983   geckodriver     INFO    Listening on 127.0.0.1:48163
1523564555013   mozrunner::runner       INFO    Running command: "/usr/bin/firefox" "-marionette" "-profile" "/tmp/rust_mozprofile.GAeX1HoEd20a"
1523564555015   geckodriver::marionette DEBUG   Waiting 60s to connect to browser
No protocol specified
No protocol specified
1523564555650   Marionette      DEBUG   Received observer notification "profile-after-change"
1523564556018   Marionette      DEBUG   Received observer notification "command-line-startup"
1523564556018   Marionette      INFO    Enabled via --marionette
No protocol specified
No protocol specified
No protocol specified

** (firefox:23214): WARNING **: 22:22:38.604: AT-SPI: Could not obtain desktop path or name

No protocol specified
No protocol specified

** (firefox:23214): WARNING **: 22:22:38.730: atk-bridge: get_device_events_reply: unknown signature

** (firefox:23214): WARNING **: 22:22:38.730: atk-bridge: get_device_events_reply: unknown signature

** (firefox:23214): WARNING **: 22:22:38.730: atk-bridge: GetRegisteredEvents returned message with unknown signature

** (firefox:23214): WARNING **: 22:22:38.731: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:38.751: AT-SPI: Could not obtain desktop path or name

No protocol specified
No protocol specified
1523564558898   Marionette      DEBUG   Received observer notification "sessionstore-windows-restored"

** (firefox:23214): WARNING **: 22:22:38.955: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:38.980: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:38.981: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:38.993: AT-SPI: Could not obtain desktop path or name

1523564559022   Marionette      DEBUG   Setting recommended pref browser.newtabpage.enabled to false
1523564559022   Marionette      DEBUG   Setting recommended pref browser.newtabpage.introShown to true
1523564559022   Marionette      DEBUG   Setting recommended pref toolkit.cosmeticAnimations.enabled to false
1523564559022   Marionette      DEBUG   Setting recommended pref datareporting.policy.dataSubmissionPolicyAccepted to false
1523564559022   Marionette      DEBUG   New connections are accepted
1523564559022   Marionette      INFO    Listening on port 38361

** (firefox:23214): WARNING **: 22:22:39.055: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:39.056: AT-SPI: Could not obtain desktop path or name

kf5.kio.core: Refilling KProtocolInfoFactory cache in the hope to find "ircs"
kf5.kio.core: Refilling KProtocolInfoFactory cache in the hope to find "mailto"
kf5.kio.core: Refilling KProtocolInfoFactory cache in the hope to find "irc"

** (firefox:23214): WARNING **: 22:22:39.103: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:39.123: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:39.123: AT-SPI: Could not obtain desktop path or name


** (firefox:23214): WARNING **: 22:22:39.194: AT-SPI: Could not obtain desktop path or name

1523564684574   webdriver::server       DEBUG   <- 500 Internal Server Error {"value":{"error":"unknown error","message":"timed out","stacktrace":""}}
1523564716804   Marionette      DEBUG   Received observer notification "xpcom-shutdown"
1523564716804   Marionette      DEBUG   Resetting recommended pref browser.newtabpage.enabled
1523564716806   Marionette      DEBUG   Resetting recommended pref browser.newtabpage.introShown
1523564716808   Marionette      DEBUG   Resetting recommended pref toolkit.cosmeticAnimations.enabled
1523564716808   Marionette      DEBUG   Resetting recommended pref datareporting.policy.dataSubmissionPolicyAccepted
1523564716808   Marionette      DEBUG   New connections will no longer be accepted