if you use an ubuntu-like system, try calinou's one-line-install command:
viewtopic.php?f=42&t=3837that is what i use. i also have the dayly ppa added to my software resources, but it only updates the file content. to actually "update" the version number i have to use calinou's command.
only updating minetest_game must be done manually.
(i envy you for being able to source-build minetest. i can do it with Battle for Wesnoth (that one is easy) but when i tried to update minetest this way i couldn't understand anything. i would be totally lost if i hadn't calinous 1-line-command ...)