[M3devel] The undefined ROOT problem, rebuilding cm3

[Rodney M. Bates]

Here is how the undefined ROOT problem happens when trying to rebuild
cm3 with itself.

I had been making the assumption that commands build, ship, clean, when
supplied to the do-cm3-*.sh scripts, did the same things as -build,
-ship, -clean supplied to the cm3 command.  Not so.

build actually does cm3 -build -override, as do buildlocal and empty
commands to the scripts. clean does cm3 -clean -override, as does cleanlocal.
There is a buildglobal command that does -build without -override, but
it also does a ship as well.  There appears to be no way to just build,
without either overriding or shipping.

So, I have been running do-cm3-*.sh with no argument (and sometimes build).
This starts a chain of events that eventually leads to an installed libm3
that always executes quake script bundle-ov.tmpl, and it requires that
either M3BUNDLE or ROOT be defined, neither of which normally is.  This
will happen trying to compile any program that uses libm3, which is just
about everything.

We should document this somewhere.