Setting up the build environment on HDD
In earlier days, Alpine Linux used a separate Gentoo build environment. Install Alpine Linux in System Disk mode i.e traditional or classic harddisk installation.
Alternates methods are to setup a clean Alpine Linux build environment inside another system, using a chroot or some form of virtualization. The host system may also be Alpine Linux, or may be something else.
Upgrade 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.
When editing the /etc/apk/repositories file, all referenced repository versions (such as v3.23 or latest-stable) therein need to be pointing to edge as follows.
Contents of /etc/apk/repositories
Contribute
Proceed to create new package or create and submit patches for Alpine Linux.