A version of your app is using a deprecated version of Go. Please upgrade before October 1, 2019. Learn more

[Anthony Zboralski]

A version of your app is using a deprecated version of Go. Please upgrade before October 1, 2019. Learn more  

WTH!! Can someone clarify? 

Do I have to migrate all my apps by October 1??? 

How come I didn't receive a message and I only saw this tiny notification line on the console today????

Are you forcing everyone to upgrade to buggy Flex and dropping support for all appengine APIs? 

[Chad Vincent]

Based on the release notes feed, it was announced in June that Go 1.9 is deprecated and no *new* versions can be deployed after October 1.  Existing versions, (e.g. GenericApp 1.5.0) will continue to run, but to release GenericApp 1.6.0 (or re-deploy 1.5.0) you'll have to do so using Go 1.11 or 1.12.

This happens fairly regularly.  Java 6 and 7 did the same thing, 8 will soon enough.  The original Python and Java AppEngine SDKs are deprecated and will stop working in 10-ish months in favor of the newer SDK that works in both Standard and Flex.

I would double-check your communication preferences to be sure that you're signed up for the right emails, and setup monitoring of the release notes page ( https://cloud.google.com/appengine/docs/standard/go/release-notes ) as a backup.

[George (Cloud Platform Support)]

You may refer to the Go “Release History” page: “each major Go release is supported until there are two newer major releases. For example, Go 1.5 was supported until the Go 1.7 release, and Go 1.6 was supported until the Go 1.8 release”.

Currently, App Engine First Generation runtime supports Go version 1.11. According to Google Cloud Platform Services Subject to the Deprecation Policy: "Google App Engine development and deployment tool support for a programming language version that is no longer publicly supported by, or receiving security updates from, the organization maintaining that programming language".

Go 1.9 deprecation was announced on the Feature Deprecation page. It should be noted that the message you received is not asking you to migrate all your apps by October 1, rather to upgrade the Go runtime environment in the First Generation runtime from version 1.9 to 1.11 before October 1, 2019.