[jcelerier]

> -- Could NOT find ZLIB (missing: ZLIB_LIBRARY) (found version "1.2.8")

that liklely means that the headers were found but not the .so. For instance maybe you have a stale zlib.h in /usr/local, but not zlib-dev installed (thus no libz.so).

You can use cmake's --debug-find first to have more info, and if that's not enough, --trace / --trace-expand ; for instance the person who wrote the FindZLIB.cmake used in that case could have done something like:

    find_library(ZLIB_LIBRARY z)
    if(ZLIB_LIBRARY) 
      if(NOT /* logic to detect if the library has a specific symbol, for instance gzopen */) 
        unset(ZLIB_LIBRARY)
      endif()
    endif()

which would result in the above error message. The main problem being that the person who wrote that script did not add a small log output to indicate why a given .so was not considered valid.