Missing cmake files from libproj-dev

[Helge Meinhard]

At least on Focal (20.04) on an x86_64 system with libproj-dev 6.3.1-1 installed, no cmake support files are installed. I would expect the following file to be installed:

/usr/share/cmake-3.16/Modules/FindPROJ.cmake or
/usr/share/cmake-3.16/Modules/FindPROJ4.cmake

As these files are not installed, builds of applications that depend on libproj and use cmake to fail.

As cmake is installable from the mainstream Ubuntu repositories, I'd expect that cmake should be supported, hence this kind of development libraries should be installed with these files.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: libproj-dev 6.3.1-1
ProcVersionSignature: Ubuntu 5.4.0-59.65-generic 5.4.78
Uname: Linux 5.4.0-59-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Mon Jan 4 19:18:39 2021
InstallationDate: Installed on 2020-11-22 (43 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: proj
UpgradeStatus: No upgrade log present (probably fresh install)

[Francesco Paolo Lovergine (frankie)]

The official proj way of supporting third-parties development is via pkg-config which does not depend on cmake or autotools. Proj upstream does not distribute any cmake snippet, cmake is only used internally as an alternative building system, mainly for Windows. Why are you supposing that it should provide cmake specific stuff? Even in that case, it could be a suggestion for upstream, eventually.

- Frankie with his DebianGis hat on

[Yohann Bénédic (yobeonline)]

Yet, the official proj documentation states that it should work with cmake (https://proj.org/development/cmake.html) and when installing from source, the following script indeed installs proj-config.cmake and the likes in /usr/local/lib/cmake/proj.

```shell
wget https://download.osgeo.org/proj/proj-7.2.1.tar.gz
tar -xzf proj-7.2.1.tar.gz
cd proj-7.2.1
mkdir build
cd build
cmake ..
cmake --build . --target install
```

[Yohann Bénédic (yobeonline)]

I found out about this very issue being discussed on proj's github page (https://github.com/OSGeo/PROJ/issues/2546). I will follow the discussion there. Sorry for the noise I made here.