We, ActiveState, are trying to build Python 3.2 (py3k branch) and get this error:

make: [build_zlib] running 'cd build/pyhg_branches_py3k-linux-x86_64-hgtip32/python/Modules/zlib && CFLAGS="-fPIC" ./configure --prefix=/home/sridharr/as/apy/branches/32a1ssl1/build/pyhg_branches_py3k-linux-x86_64-hgtip32/ExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIxExTAcTiVePyThOnPrEfIx && make && make install'
Checking for gcc...
Checking for shared library support...
Tested gcc -w -c -fPIC -fPIC ztest8832.c
Tested gcc -shared -Wl,-soname,libz.so.1,--version-script,zlib.map -fPIC -fPIC -o ztest8832.so ztest8832.o
/usr/bin/ld: cannot open linker script file zlib.map: No such file or directory
collect2: ld returned 1 exit status
No shared library support; try without defining CC and CFLAGS
Building static library libz.a version 1.2.5 with gcc.
Checking for off64_t... Yes.
Checking for fseeko... Yes.
cp: cannot stat `zconf.h.in': No such file or directory
Checking for unistd.h... Yes.
Checking whether to use vs[n]printf() or s[n]printf()... using vs[n]printf().
Checking for vsnprintf() in stdio.h... Yes. 
Checking for return value of vsnprintf()... Yes.
Checking for attribute(visibility) support... Yes.
./configure: 596: cannot open zlib.pc.in: No such file
gcc -fPIC -D_LARGEFILE64_SOURCE=1   -c -o example.o example.c
gcc -fPIC -D_LARGEFILE64_SOURCE=1   -c -o adler32.o adler32.c
gcc -fPIC -D_LARGEFILE64_SOURCE=1   -c -o compress.o compress.c
gcc -fPIC -D_LARGEFILE64_SOURCE=1   -c -o crc32.o crc32.c
gcc -fPIC -D_LARGEFILE64_SOURCE=1   -c -o deflate.o deflate.c
make: *** No rule to make target `gzguts.h', needed by `gzclose.o'.  Stop.

Running a ./configure Modules/zlib leads to:

sridharr@whymac:~/code/o/py/py3k/Modules/zlib > ./configure 
Checking for gcc...
Checking for shared library support...
Building shared library libz.1.2.5.dylib with gcc.
Checking for off64_t... No.
Checking for fseeko... Yes.
cp: zconf.h.in: No such file or directory
Checking for unistd.h... Yes.
Checking whether to use vs[n]printf() or s[n]printf()... using vs[n]printf().
Checking for vsnprintf() in stdio.h... Yes.
Checking for return value of vsnprintf()... Yes.
Checking for attribute(visibility) support... Yes.
./configure: line 575: zlib.pc.in: No such file or directory

***

Is zlib.pc.in missing by accident?

***

I can run ./configure in Modules/zlib for Python trunk (2.7) though.

Sifting through the changelog, I discovered that this commit must have introduced this bug http://svn.python.org/view/python/branches/py3k/Modules/zlib/configure?r1=56849&r2=83296 

Marin, perhaps you forgot to checkin zlib.pc.in? Have you tried running ./configure (under Modules/zlib) on a OSX or Linux machine?