CMake Warning \(dev\) at CMP0028-WARN-iface\.cmake:3 \(target_link_libraries\):
  Policy CMP0028 is not set: Double colon in target name means ALIAS or
  IMPORTED target.  Run "cmake --help-policy CMP0028" for policy details.
  Use the cmake_policy command to set the policy and suppress this warning.

  The link interface of target "iface" contains:

    External::Library

  but the target was not found.  Possible reasons include:
(
    \*[^
]+)*

Call Stack \(most recent call first\):
  CMakeLists\.txt:[0-9]+ \(include\)
This warning is for project developers.  Use -Wno-dev to suppress it.