If “some C++ program” uses zlib, then implicitly. It uses a bunch of libraries, Qt or assimp i.e., but not ngsolve. To solve the problem i tried to download zlib from GnuWin32 on sourceforge and set ZLIB_LIBRARY and ZLIB_INCLUDE_DIR. But the problem further consists.
It is also confusing that it referes to ngsolve-v6.2.2104 not ngsolve-v6.2.2204. I uninstalled ngsolve-v6.2.2104 and installed ngsolve-v6.2.2204, this is the event the problem occures.
So it is not a problem of “missing” zlib i think, zlib is present at least in ngsolve-v6.2.2204 but also Qt or assimp ship with some copy i know. It is a reference problem …
I also asked in the ngsolve forum but no solution until now, and since it is very cmake specific in my point of view i hoped to get some knowledge about how cmake looks up for libs on windows …
even the global and user specific path variables did not contain any reference to ngsolve-v6.2.2104 …