* configure.in:

  - Check for zlib library and headers.

configure.in

@@ -83,6 +83,10 @@ AC_CHECK_LIB(curl, curl_easy_init,
 
 AC_SUBST(BDBLIB)
 
+AC_CHECK_LIB(z, gzopen,
+	[AC_CHECK_HEADER(zlib.h, [], AC_MSG_ERROR([failed: zlib.h not found]))],
+	AC_MSG_ERROR([failed: Need libz]))
+
 dnl Converts the ARCH to be something singular for this general CPU family
 dnl This is often the dpkg architecture string.
 dnl First check against the full canonical canoncial-system-type in $target

debian/changelog

@@ -13,6 +13,8 @@ apt (0.7.26~exp5) UNRELEASED; urgency=low
     - Link against zlib (in apt-pkg/makefile) and add zlib build dependency.
     - [ABI BREAK] This introduces a new protected member of FileFD and changes
       the behaviour of FileFd for reading gzipped files.
+  * configure.in:
+    - Check for zlib library and headers.
   * apt-pkg/deb/debindexfile.cc:
     - If we do not find uncompressed package/source/translation indexes, look
       for gzip compressed ones.