I think we need an easy way to set a default for this behaviour from within configure.ac, similar to AC_PREFIX_DEFAULT(), so that the end-user doesn't have to pass a bunch of options to configure just to get the build to work sensibly.
I have nothing against the idea, but my immediate goal is more basic: restore the previous behavior without losing the new configure benefits entirely. The current workaround I use is described below. Thanks for sending that code. --best, karl.