configure statement for R-devel with updated zlib in user account

I'm aware R-devel no longer includes zlib. This works find on
up-to-date Linux systems.

On the older Centos 6 cluster at KU, they have zlib tool old for
R-devel. The R-devel configure fails thus:

checking if zlib version >= 1.2.5... no
checking whether zlib support suffices... configure: error: zlib
library and headers are required

In other software, I've seen this kind of thing, so I installed zlib
1.2.8 into $HOME/packages and I can verify that the right pieces are
installed there.

Now I need you to tell me how to tell R to use that. Guesses so far:

$ export PATH=$HOME/packages/bin:$PATH
$ export LD_LIBRARY_PATH=$HOME/packages/lib:$LD_LIBRARY_PATH

What R's configure statement needs to find zlib in my user account?

In R-devel, the ./configure --help doesn't give me a simple-enough
explanation of what I'm supposed to do. I thought I had a solution by
adding this

--with-libpth-prefix=$HOME/packages

but still rejection, new zlib not found.

Paul E. Johnson
Professor, Political Science        Director
1541 Lilac Lane, Room 504      Center for Research Methods
University of Kansas                 University of Kansas
http://pj.freefaculty.org              http://crmda.ku.edu