[tlbuild] LuaMetaTeX for TeX Live

[Karl Berry]

            cd ...
            cmake ...
    similarly to what we do for asy?

I am strongly opposed to this. It basically shoves the
configuration/build work onto every builder, instead of doing it
correctly (in the source tree) in the first place. Dealing with asy
build+install is approximately more work than everything else put
together. Let's not add another special case like that.

For asy, we more or less have to do it that way because asy has a
terrific load of dependencies that the rest of the tree does not.
But this is (thankfully) not the case for lmtx, as I understand it.

My counter-proposal, following Luigi's idea, is to treat lmtx like
biber, which is a different (and much simpler) kind of special case: I
import your binaries(+sources) at whatever times (weekly, monthly, on
request, ...) you specify, entirely with my import-into-TL script. I
expect this would be easy.

Doing it this way eliminates the need for any new work or procedures for
the builders, any dependency on cmake in TL, and any new autotools
work. Why continue to put ourselves through this agony? -k