zlib missing?
 

Upon attempting to build Celestia 1.5.0 or 1.5.1 I encounter the following error:

checking for deflate in -lz... no
configure: error: zlib not found.

This issue arises despite the fact I have the following packages installed:

zlib-bin - compression library - sample programs
zlib1g - compression library - runtime
zlib1g-dev - compression library - development
zlibc - Uncompressing C Library
zziplib-bin - library providing read access on ZIP-archives - binaries

I have also tried to remove the packages and reinstall them, to no avail.

First try this:
Then:
You should see something like:
00001c00 T deflate

If that is there, then you'll have to debug the configure script. Your options are run it with a sh -x ./configure or just vi the file then search for the error text and then attempt to recreate the test program and compile line.

what distro are you building on and what gui are you building for Gnome,kde
this is what i use for my custom SVN build
./configure --prefix=/opt --with-gnome --enable-cairo --with-cspice-dir=/opt/cspice --with-lua --disable-nls