cmake configuration build error

[adithyahk46]

osgEarth Version (required):
master branch

Description of the problem:
osgearth-target.cmake hard coded the paths of osg libs

What you have tried:
the libraries have build in other system, i get those libs and i tried to configure osgearth using cmake and build the project but its faild because its expecting osg libs from older paths

13:19:45: Starting: "C:\Qt\Tools\CMake_64\bin\cmake.exe" --build C:/Users/pnmt1054/Adithya_working_directory/QT_PROJECTS/OsgEarth_Cmake/build --target all
ninja: error: 'D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgManipulator.lib', needed by 'src/app/OsgEarthViewer.exe', missing and no known rule to make it

osgearth-target.cmake linked osg libs with hardcoded paths

set_target_properties(osgEarth::osgEarth PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
INTERFACE_LINK_LIBRARIES "D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgManipulator.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgShadow.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgSim.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgViewer.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgGA.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgUtil.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgText.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osgDB.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/osg.lib;D:/vcpkg_osgearth/vcpkg/installed/x64-windows/lib/OpenThreads.lib"
)

[gwaldron]

Thank you for bringing this to our attention. This is due to the fact that the OSG dependencies use the old-style FindOpenSceneGraph technique and that doesn't support package-relative paths. We are looking into a fix. Are you doing a static build?

[adithyahk46]

Yes, it's a static build, replacing hardcoded line like below can resolve the problem

set_target_properties(osgEarth::osgEarth PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
INTERFACE_LINK_LIBRARIES "${OPENSCENEGRAPH_LIBRARIES}"
)

[gwaldron]

Can you please take a look at this PR and see if you agree with the fix?
#2991