slackbuilds/system/slackrepo

slackrepo - Automated SlackBuild package builder

slackrepo is a tool for making and managing package repositories on
Slackware, by building from repositories of SlackBuilds.

Features:
  * Clean repeatable building, including dependencies
  * Highly automated (no interaction required)
  * Package updates detected by tracking upstream git revisions
  * Output repositories suitable for use with slackpkg+

You'll most likely want to also install slackrepo-hints.

Optional dependency: fakeroot