Sorry that I keep running off in the wrong direction.
They control the runtime in a very heavy-handed, opaque way to lock it down and I doubt that would ever change. New runtimes will be 100% up to Google to implement and they seem not to be a high priority in general - Java seems to be favored for the enterprise people and Go and Python have had involvement from the respective language creators... Google has only so many major language creators ;)
Just part of how App Engine is a closed platform really (although it's not like all of Heroku is open either)
They control the runtime in a very heavy-handed, opaque way to lock it down and I doubt that would ever change. New runtimes will be 100% up to Google to implement and they seem not to be a high priority in general - Java seems to be favored for the enterprise people and Go and Python have had involvement from the respective language creators... Google has only so many major language creators ;)
Just part of how App Engine is a closed platform really (although it's not like all of Heroku is open either)