CMake 3.31 warning due to path normalization

[dmnks]

When configuring rpm on Fedora 43 (Rawhide) that ships with cmake 3.31, the following warning is printed:

CMake Warning (dev) at plugins/CMakeLists.txt:16 (install):
  Policy CMP0177 is not set: install() DESTINATION paths are normalized.  Run
  "cmake --help-policy CMP0177" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.
This warning is for project developers.  Use -Wno-dev to suppress it.

More details: https://cmake.org/cmake/help/latest/policy/CMP0177.html

This appears to be related to:

install(FILES org.rpm.conf DESTINATION ${dbus-1_DATADIR}/dbus-1/system.d/)

I'm not sure why the warning is printed, though, given the following (emphasis mine):

This policy was introduced in CMake version 3.31. It may be set by cmake_policy() or cmake_minimum_required(). If it is not set, CMake will warn if it detects a path that would be different if normalized, and uses OLD behavior.

Anyway, this probably needs a closer look, just to make sure we're not breaking any install paths.

[dmnks]

Oh, now I know why. The value of ${dbus-1_DATADIR} is /usr/lib64/pkgconfig/../../share. Hmm.

[dmnks]

I guess this is a non-issue. The resulting path that install() gets is different indeed but apparently it gets normalized at some later point anyway since the file does (and always did) get installed into the right location, i.e. /usr/share.