Include:Upgrading to Edge
An upgrade of Alpine Linux from a stable version to the rolling development version edge basically requires the same steps as Upgrading to latest release.
The crucial difference is, that when editing the /etc/apk/repositories file, all referenced repository versions (such as v3.2 or latest-stable) therein need to be pointing to edge.
After the upgrade, the currently installed edge release may be checked with
cat /etc/alpine-release
and referring to the build date that is attached to the release.