The proj package is built with Autotools, not CMake.
Ubuntu does not maintain the proj package, so this will not get fixed by filing a bug in Launchpad.
Including the CMake files in libproj-dev won't be sufficient, as it will take several releases until this change finds its way into the package in Ubuntu. But that doesn't get it included in other distributions.
You should include a FindPROJ.cmake in your project and not rely on upstream to have installed the file.
The proj package is built with Autotools, not CMake.
Ubuntu does not maintain the proj package, so this will not get fixed by filing a bug in Launchpad.
Including the CMake files in libproj-dev won't be sufficient, as it will take several releases until this change finds its way into the package in Ubuntu. But that doesn't get it included in other distributions.
You should include a FindPROJ.cmake in your project and not rely on upstream to have installed the file.