[CMake] Error: XXX is not set. It must be set .... XXXConfig.cmake

[ope]

Hi,

the following error occoured with the entries in my CMakeList.txt

find_package(Curl REQUIRED)
include_directories(${Curl_INCLUDE_DIR})
link_directories(${Curl_LIBRARIES})

with cmake CURL_DIR="/usr"

CMake Error: Curl_DIR is not set.  It must be set to the directory
containing CurlConfig.cmake in order to use Curl.

The same with zlib. What is wrong here?

Thanks
Olaf