Using Arduino.mk 1.6.0 with pro mini on Ubuntu 18.10.

I'm trying to get Arduino.mk going for the first time. I've checked out release 1.6.0 of GitHub - sudar/Arduino-Makefile: Makefile for Arduino sketches. It defines the workflows for compiling code, flashing it to Arduino and even communicating through Serial., and am trying to build the Blink example.

When I try to build for BOARD_TAG="pro", or "mega", or for any target other than "uno", it creates build an output directory for my target (build-pro), but it still builds into the default build-uno.

The makefile aborts after compilation, since it's looking for .o files in the correct target, but they've been built into build-uno.

Are there any other Linux makefile users here who can suggest what I might be doing wrong?

[Solved: the default Makefile had an additional "include ../../Arudino.mk" at the top of the file, when it should be at the bottom.]