I went straight to your code and didn't double check the timestamps on your post against your repo and was quite perplexed by what might be going wrong (FWIW the makefile was my guess but it was updated in your code repo!?). But after reading this whole thread it became clear...! :)

I suspect that there is an element of "curse of knowledge" going on here re the docs and you missing the Makefile, although I did double check the docs and the Makefile does get quite a few mentions:

root@tkldev4 .../products/tkldev# grep -ir makefile docs/
docs/tips.rst:root.sandbox depends on root.patched in the Makefile so after removing
docs/tips.rst:Did you know that the Makefile is self documenting?::
docs/tips.rst:    2) product Makefile
docs/appliance-checklist.rst:Makefile
docs/appliance-checklist.rst:    `Makefile `_.
docs/README.rst:      3 core/Makefile
docs/README.rst:    root@tkldev fab/products# cat core/Makefile 
docs/README.rst:       5 lamp/Makefile
docs/appliance-buildcode-dir.rst:   |-- Makefile
docs/development/howto-new-app.rst:        These common bases are used via the Makefile, here is a list of appliances which use
docs/development/howto-new-app.rst:        want to do is create a Makefile.
docs/development/howto-new-app.rst:            all appliance-base specific common makefiles must be included BEFORE turnkey.mk
docs/development/howto-new-app.rst:        For our lamp based appliance our Makefile will be as follows
docs/development/howto-new-app.rst:        .. code-block:: Makefile
docs/development/howto-new-app.rst:Makefile
docs/development/howto-new-app.rst:    1. Copy the makefile from core
docs/development/howto-new-app.rst:    2. Set any appropriate build flags within the makefile
docs/development/walkthrough.rst:Makefile
docs/development/walkthrough.rst:	root@tkldev products/core# cat Makefile 
docs/development/walkthrough.rst:The `Makefile`_ includes `common/mk/turnkey.mk`_, which defines default values for
docs/development/walkthrough.rst:Makefile. It's designed to be highly configurable and extensible.
docs/development/walkthrough.rst:.. _Makefile: https://github.com/turnkeylinux-apps/core/blob/master/Makefile
docs/development/new.rst:  the ``Makefile`` and ``overlay/etc/confconsole/services.txt``.
docs/development/new.rst:start with the ``Makefile``, ``plan`` and finally ``conf.d and

Having said that the TKLDev docs are a bit of a mess. Lots of people have contributed in the past and I have added new bits and updated some bits but others haven't been touched for ages... A fresh set of eyes over that would be incredibly useful! :) TBH, perhaps it's better to edit the docs before you become too familiar with TKLDev?!

PS I tried building using your buildcode and it successfully built to ISO. I didn't test the ISO itself though.

My main observations with the docs are that they're hard to follow - I have like 8-10 tabs of docs open right now and jump around a lot - so of the many mentions of the Makefile, none happened to be at the right places where I was looking while hacking on this yesterday! Mainly, it seems like there isn't a single linear "flow" thru the documentation for somebody trying to get oriented to using TKLdev. That, and the outdated bits that are sprinkled around.

Great feedback, thanks! I suspect that part of the issue is that most of the docs were written by Liraz many years ago. Then I've added to them and tweaked bits here and there, but not revised them start to finish...

I think that probably the way to go would be to have 2 (or perhaps even 3) "sets" of docs. A high level overview and a lower level, more detailed view (with perhaps a mid level view as well?).

If you do get a chance to have a look, please do as documentation is generally an area where we would love to do much better. I have tried to make improvements along the way, but most of my efforts re development docs have been adding new info rather that improving what already there and curse of knowledge is always an issue.