I noted on IRC a request for this; it seems not unreasonable as there
are distributions with pretty broken DocBook processing configurations
where a straight "make" will generate a bunch of error messages and
complaints about the documentation build.  It's going to be much more
normal for people to want to build the software and only hear gripes
about problems WITH THAT.

Here is a patch to the main GNUmakefile.in, which, at ./configure time,
generates a GNUmakefile that ought to more or less do the trick.

I'm not going to straight commit just yet this as it may need some
dialogue from package makers as it could break their packages.  There
are several side-effects that might break things and/or be considered
broken:

1.  In order to build docs, package makers need to add an additional
"make doc" step.  (That might break things, but definitely isn't broken.)

2.  There is no direct way to request installation of docs from a make
invocation from the main directory; you must do "cd doc; make install"

3.  There is no direct way to clean out docs from a make invocation from
the main directory; as with (2), you must do "cd doc; make clean"

diff -c -r1.20 GNUmakefile.in
*** GNUmakefile.in    27 May 2005 20:46:38 -0000    1.20
--- GNUmakefile.in    30 May 2005 15:59:42 -0000
***************
*** 28,48 ****
    $(wildcard share/*) \
    $(wildcard makefiles/*)
 
 
  all:
!     @for subdir in src tools doc ; do \
        $(MAKE) -C $$subdir $@ || exit; \
      done && \
      echo "All of Slony-I is successfully made. Ready to install"
 
  install    installdirs:
!     @for subdir in src tools doc ; do \
        $(MAKE) -C $$subdir $@ || exit; \
      done && \
      echo "All of Slony-I is successfully installed"
 
  clean:
!     @for subdir in src doc tools ; do \
        $(MAKE) -C $$subdir $@ ; \
      done ;\
        rm -f postgres.imp
--- 28,49 ----
    $(wildcard share/*) \
    $(wildcard makefiles/*)
 
+ DEFAULTBUILDS=src tools
 
  all:
!     @for subdir in $(DEFAULTBUILDS) ; do \
        $(MAKE) -C $$subdir $@ || exit; \
      done && \
      echo "All of Slony-I is successfully made. Ready to install"
 
  install    installdirs:
!     @for subdir in $(DEFAULTBUILDS) ; do \
        $(MAKE) -C $$subdir $@ || exit; \
      done && \
      echo "All of Slony-I is successfully installed"
 
  clean:
!     @for subdir in $(DEFAULTBUILDS) ; do \
        $(MAKE) -C $$subdir $@ ; \
      done ;\
        rm -f postgres.imp