User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36 Steps to reproduce: Geckodriver: 0.22 Platform: Windows Firefox: Nightly 64.0a1 (2018-09-20) (64-bit) Selenium: HEAD, Java binding Sample code: driver.installExtension(Paths.get("c:\\Temp\\search_encrypt-2.8.3-an+fx.xpi")); 0.22 trace log: 1537532269894 webdriver::server DEBUG -> POST /session/ff9a2565-6cd5-4442-b86d-0bdc3c0ac9dd/moz/addon/install { "path": "c:\\Temp\\search_encrypt-2.8.3-an+fx.xpi" } 1537532269895 webdriver::server DEBUG <- 400 Bad Request {"value":{"error":"invalid argument","message":"data did not match any variant of untagged enum Helper","stacktrace":""}} 0.21 trace log: 1537527046406 webdriver::server DEBUG -> POST /session/3f70bc2e-cde0-4326-bee8-310df0708a95/moz/addon/install { "path": "c:\\Temp\\search_encrypt-2.8.3-an+fx.xpi" } 1537527047014 Marionette TRACE 0 -> [0,2,"Addon:Install",{"path":"c:\\Temp\\search_encrypt-2.8.3-an+fx.xpi","temporary":false}] 1537527052973 Marionette TRACE 0 <- [1,2,null,{"value":"@searchencrypt"}] 1537527052974 webdriver::server DEBUG <- 200 OK {"value":"@searchencrypt"}

The problem is that I assumed the `temporary` flag is required, while it is optional. As such missing the key will cause this failure. I will have a look at this early next week.

With the Serde refactoring we have made this flag mandatory. This patch reverts that change, and allows it to be skipped.

Comment on attachment 9012504 [details] Bug 1493149 - [geckodriver] "temporary" flag in AddonInstallParameters has to be optional. r?ato Andreas Tolfsen ❲:ato❳ has approved the revision.

Pushed by hskupin@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/6155b2f3b9c1 [geckodriver] "temporary" flag in AddonInstallParameters has to be optional. r=ato

Please uplift the test-only patch to beta to fix a regression with geckodriver.