[Pkg-cmake-team] Bug#1087550: cmake-data: FindZLIB.cmake fails to populate ZLIB_INCLUDE_DIRS and ZLIB_LIBRARIES

[Andrius Merkys]

Package: cmake-data
Version: 3.31.0-1
Severity: important
Affects: macromoleculebuilder
Control: block 1086362 by -1

Hello,

FindZLIB.cmake does not populate the declared result variables 
ZLIB_INCLUDE_DIRS, ZLIB_LIBRARIES and so on. In fact, it seems as if it 
does not find ZLIB at all (ZLIB_FOUND is undefined). Minimal failing 
example:

cmake_minimum_required(VERSION 3.31)
project(test LANGUAGES CXX)
find_package(ZLIB REQUIRED)

Resulting CMakeCache.txt does not contain neither ZLIB_INCLUDE_DIRS nor 
ZLIB_LIBRARIES.

zlib1g-dev 1:1.3.dfsg+really1.3.1-1 is installed.

Interestingly, it seems that this problem persists for a longer time. I 
tried running the same MFE (without cmake_minimum_required()) on Ubuntu 
20.04 (cmake-data 3.16.3-1ubuntu1.20.04.1, zlib1g-dev 
1:1.2.11.dfsg-2ubuntu1.5) and the declared result variables 
ZLIB_INCLUDE_DIRS and ZLIB_LIBRARIES are not set there as well.

Not sure whether this issue is Debian-specific or belongs with the 
upstream. I spotted it when dealing with #1086362.

Andrius