CMake error with external freetype

Support
1

I am trying to compile VTK using conan for installing the dependencies. However, the packages generated by conan already provide freetype, as its a dependency of Qt, and when I try to configure VTK, I get the following error:

[cmake] CMake Error at VTK/CMake/vtkModule.cmake:4139 (add_library):
[cmake]   add_library cannot create target "freetype" because an imported target with
[cmake]   the same name already exists.
[cmake] Call Stack (most recent call first):
[cmake]   VTK/ThirdParty/freetype/vtkfreetype/CMakeLists.txt:54 (vtk_module_add_module)

I have tried to set VTK_MODULE_USE_EXTERNAL_vtkfreetype and VTK_MODULE_USE_EXTERNAL_freetype to true, without success.

Is there anyway to compile VTK with external freetype?

2

Hello,

If freetype is being build by Conan independently, then I believe you need to disable it in VTK configuration and add freetype as a required package in the VTK’s Conan recipe. If you enable it in VTK’s CMakeLists.txt, then freetype will be built again with likely adverse results.

best,

PC

3

I am not sure I understand. What do you mean with VTKs conan recipe? I havent found any recipe for VTK. What I did was to create a conanfile to specify VTK dependencies, mainly Qt6, and when I tried to use the Qt6Config package generated by Conan, that included freetype.

How can I disable freetype in VTK CMakeLists? I tried VTK_MODULE_USE_EXTERNAL_freetype/vtkfreetype, but none of them work. I could of course rework a lot of parts of VTKs CMakeLists to fetch an external freetype, but I was expecting some supported way of using an external freetype.

4

How do you use Conan to build VTK?

5

Actually I am building ParaView, so I created a conanfile to specify Qt as a dependency. Then I just run cmake normally, but specifying the conan_toolchain file produced by conan, which makes cmake use the FooConfig.cmake packages created by conan.

That brings freetype (Qt has a dependency on freetype), and VTK compilation fails because it sees there is already an external freetype and it can’t compile its own

6

Well, then you need to disable it when running CMake to configure VTK. You know you can pass CMake varibales via command line. E.g.: cmake ... -DVTK_MODULE_USE_EXTERNAL_vtkfreetype=true -D..., right?

7

Not sure if you read my question, but I clearly said I tried using that option without success…

8

This is because the target name for VTK::freetype is freetype internally. Fixing this issue would resolve it. I suppose it is higher priority now.