configure args, BUILD_DEFS in a Makefile.common context

[Greg Troxel <gdt%lexort.com@localhost>]

In ups-nut, there are multiple path args for configure for state/pid.
The upstream situtation is muddled for historical reasons.

There is a Makefile.common, which sets some of these, and currently some
others are set individually.  BUILD_DEFS additions are inconsistent, and
part of the issue is that a path being set in Makefile.common doesn't
imply that anything installed by a split package actually uses that
path.

Overall, I lean to:

  Set all the paths in Makefile.common, so that all split builds are
  consistent.  Don't worry that things are specified without being
  proven necessary.

  Add BUILD_DEFS in Makefile.common matching the path setting, without
  worrying that it isn't proven that any package needs it.

This will lead to over-setting of BUILD_DEFS, but I'm having a hard time
getting upset about that, compared to risk of under-setting (which I am
also not really upset about, not understandin which Bad Thing might
happen, despite getting it that it's wrong).

The guide is silent on BUILD_DEFS, and the help topic= implies that it
is a clue to the user about what can be set, without explaining the
consequences of "their values will be recorded in the binary package."


Does anybody want to make an argument that this set-it-always approach
is wrong?