How to link cuda library to cpp project/files with Cmake?

I am trying to write a gui program using the gtk libraries and do some matrix operations with the cuda libraries, however I get an error when trying to link the cuda libraries in my project. My Cmake looks like this:

cmake_minimum_required(VERSION 3.21)
project(untitled1)

set(CMAKE_CXX_STANDARD 14)


find_package(CUDAToolkit)
include_directories(${CUDA_INCLUDE_DIRS})
link_directories(${CUDA_LIBRARY_DIRS})

find_package(PkgConfig REQUIRED)
pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
include_directories(${GTK3_INCLUDE_DIRS})
link_directories(${GTK3_LIBRARY_DIRS})

add_definitions(${GTK3_CFLAGS_OTHER})

add_executable(untitled1 main.cpp bob.h bob.cu)
target_link_libraries(untitled1 ${GTK3_LIBRARIES} ${CUDA_LIBRARIES} ${CUDA_CUDART_LIBRARY})

But I get the following error

-- Unable to find cuda_runtime.h in "/usr/lib/cuda/include" for CUDAToolkit_INCLUDE_DIR.
-- Unable to find cudart library.
-- Could NOT find CUDAToolkit (missing: CUDAToolkit_INCLUDE_DIR CUDA_CUDART) (found version "11.2.67")
-- Configuring done
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
CUDA_CUDART_LIBRARY (ADVANCED)

I am on Pop OS 21.10 (Ubuntu), I can use the Cuda libraries and nvcc outside of this project, so I know it is installed and working properly. I just don't know how to link the cuda libraries to a non cuda project.

Edit: Working CMakeLists.txt down below thx to dhyun

# Set the minimum version of cmake required to build this project
cmake_minimum_required(VERSION 3.21)

# Set the name and the supported language of the project
project(final CUDA)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CUDA_STANDARD 14)

# Use the package PkgConfig to detect GTK+ headers/library files
find_package(PkgConfig REQUIRED)
pkg_check_modules(GTK3 REQUIRED gtk+-3.0)

# Setup CMake to use GTK+, tell the compiler where to look for headers
# and to the linker where to look for libraries
include_directories(${GTK3_INCLUDE_DIRS})
link_directories(${GTK3_LIBRARY_DIRS})

# Add other flags to the compiler
add_definitions(${GTK_CFLAGS_OTHER})

# Add an executable compiled from files:
add_executable(final main.cu showtext.h)

target_link_libraries(final ${GTK3_LIBRARIES})

# Idk what this does or if it's necessary, but it works with it and was there on creation
# So I'm keeping it :)
set_target_properties(final PROPERTIES
        CUDA_SEPARABLE_COMPILATION ON)

Solution

I can't speak for your exact setup, but I've had success with CMake and CUDA on Ubuntu by directly enabling CUDA as a language in the project declaration rather than using find_package(CUDAToolkit).

Something like this:

cmake_minimum_required(VERSION 3.21)
project(untitled1 LANGUAGES CUDA CXX)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CUDA_STANDARD 14)

find_package(PkgConfig REQUIRED)
pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
include_directories(${GTK3_INCLUDE_DIRS})
link_directories(${GTK3_LIBRARY_DIRS})

add_definitions(${GTK3_CFLAGS_OTHER})

add_executable(untitled1 main.cpp bob.h bob.cu)
target_link_libraries(untitled1 ${GTK3_LIBRARIES})

I believe cudart is linked automatically, but you will need to specify any other libraries you use (cufft, cublas, cudnn, etc.).