Using the --silence hackery from Jacob Berkman I found a way to finally STFU at least libtool. In your configure.ac add:

changequote(,)dnl
LIBTOOL=“\$(QUIET_LT)${LIBTOOL}”
changequote([,])dnl

Add a Makefile.decls file to the root of your project, containing:

QUIET_LT = @echo ‘    ’ LIBTOOL $@;

And include it in every Makefile.am:

include $(top_srcdir)/Makefile.decls

This will silence all libtool invocations; you can make this all conditional, obviously: just sorround the QUIET_* declarations with if VARIABLE...endif and define VARIABLE using AM_CONDITIONAL in your configure template.

Now, I’ll just have to find a way to make gcc shut up¹, and so the saga will end with a third chapter.

1. no, you cannot redefine CC, as it will be invoked by libtool as well [↩]