I did it the dirty way. I just edited the relevant Makefile in build/.... and deleted the tuxmail dependancy. Hey, I was making a test-environment, who cares if tuxmail is compiled or not? :-)
In the very latest pull (just before the weekend) the problems with tuxmail seems to have vanished, and it's now building. I have not tested it.
Be aware also of the instructions on the official Dreambox board on
www.dream-multimedia-tv.de. I didn't know of it until a week or so ago.
These instructions are from early December, and I have the feeling they are already slightly outdated. At least I ended up by following his advice on changing DISTRO and removing CVS_DATE etc, while I'm not anymore doing any masking. When I changed the config , just to be sure to be sure, I deleted my cache and the whole of tmp, and remade the whole lot. I'll tell you, I'm sick and tired of watching glibc being recompiled!
I do have some strangeness still left somewhere, or maybe something's been deliberately changed. In the latest build, enigma is running single-threaded on my machine, and while this is probably more stable etc, it also makes it unresponsive as hell and a real pain in the arse to use. It could be something I have done, though, or maybe there's another magic variable that should be set or deleted somewhere. Or maybe there are some 7020 optimizations that's hurting the 7000. There's a definite lack of documentation, and this probably won't improve until the Dream developers have finished the first release for the 7020. I guess they are pretty busy at the moment...