undefined reference to `ImGui::

[zih-an]

I use vcpkg manifest to install imgui, vcpkg.json:

{
  "name": "vcpkgtest",
  "version": "1.0.0",
  "description": "learn vkpg & glfw & imgui & cmake",
  "dependencies": [
    "glfw3",
    {
      "name": "imgui",
      "features": ["glfw-binding", "opengl3-binding"]
    }
  ]
}

CMakeLists.txt:

cmake_minimum_required(VERSION 3.25)
project(vcpkg_test)

set(CMAKE_CXX_STANDARD 17)

add_executable(vcpkg_test main.cpp)
## link packages
find_package(OpenGL REQUIRED)
target_link_libraries(vcpkg_test PRIVATE opengl32)

find_package(glfw3 CONFIG REQUIRED)
target_link_libraries(vcpkg_test PRIVATE glfw)

find_package(imgui CONFIG REQUIRED)
target_link_libraries(vcpkg_test PRIVATE imgui::imgui)

I got the folloing error messages:

[ 50%] Linking CXX executable vcpkg_test.exe
CMakeFiles\vcpkg_test.dir/objects.a(main.cpp.obj): In function `main':
E:/Fdisk/programming/vcpkg_test/main.cpp:26: undefined reference to `ImGui::DebugCheckVersionAndDataLayout(char const*, unsigned long long, unsigned long long, unsigned long long, unsigned long long, unsigned long long, unsigned long long)'
E:/Fdisk/programming/vcpkg_test/main.cpp:27: undefined reference to `ImGui::CreateContext(ImFontAtlas*)'
E:/Fdisk/programming/vcpkg_test/main.cpp:28: undefined reference to `ImGui::GetIO()'
E:/Fdisk/programming/vcpkg_test/main.cpp:29: undefined reference to `ImGui_ImplGlfw_InitForOpenGL(GLFWwindow*, bool)'
E:/Fdisk/programming/vcpkg_test/main.cpp:30: undefined reference to `ImGui_ImplOpenGL3_Init(char const*)'
E:/Fdisk/programming/vcpkg_test/main.cpp:38: undefined reference to `ImGui_ImplOpenGL3_NewFrame()'
E:/Fdisk/programming/vcpkg_test/main.cpp:39: undefined reference to `ImGui_ImplGlfw_NewFrame()'
E:/Fdisk/programming/vcpkg_test/main.cpp:40: undefined reference to `ImGui::NewFrame()'
E:/Fdisk/programming/vcpkg_test/main.cpp:42: undefined reference to `ImGui::Begin(char const*, bool*, int)'
E:/Fdisk/programming/vcpkg_test/main.cpp:43: undefined reference to `ImGui::Text(char const*, ...)'
E:/Fdisk/programming/vcpkg_test/main.cpp:44: undefined reference to `ImGui::End()'
E:/Fdisk/programming/vcpkg_test/main.cpp:45: undefined reference to `ImGui::Render()'
E:/Fdisk/programming/vcpkg_test/main.cpp:46: undefined reference to `ImGui::GetDrawData()'
E:/Fdisk/programming/vcpkg_test/main.cpp:46: undefined reference to `ImGui_ImplOpenGL3_RenderDrawData(ImDrawData*)'
E:/Fdisk/programming/vcpkg_test/main.cpp:56: undefined reference to `ImGui_ImplOpenGL3_Shutdown()'
E:/Fdisk/programming/vcpkg_test/main.cpp:57: undefined reference to `ImGui_ImplGlfw_Shutdown()'
E:/Fdisk/programming/vcpkg_test/main.cpp:58: undefined reference to `ImGui::DestroyContext(ImGuiContext*)'
collect2.exe: error: ld returned 1 exit status

I've directly used the source code of imgui before to run the main.cpp successfully.

It's my first time to use vcpkg+imgui, but it seems that the lib missed something. I'm sure that ["glfw-binding", "opengl3-binding"] are installed because I can see the corresponding header files in ./cmake-build-debug/vcpkg_installed/x64-windows/include. So what's the problem?

[PathogenDavid]

target_link_libraries(vcpkg_test PRIVATE imgui::imgui)

I've never used vcpkg with CMake before, but this doesn't look right to me. I would assume it's supposed to be target_link_libraries(vcpkg_test PRIVATE imgui).

[zih-an]

Thanks for your reply, but it seems that imgui::imgui is special for vcpkg.

[zih-an]

Anyway, I've decided to add imgui manually in an extern folder, but I'm still wondering how to use find_package & target_link_libraries on win11 without C++ package manager like vcpkg. Could you give me a project example so that I can explore on my own?

[Ownie]

Almost 3 years later, this issue persists.

[ocornut]

It means you are not correctly linking your project with ImGui code and its backends.

[Ownie]

I can add it and link it myself traditionally. But when you use vcpk it just doesn't seem to work. Exact same issue as above but I'm using SDL instead of GLFW.

vcpkg.json:

{
  "name": "kontrol",
  "version": "1.0.0",
  "dependencies": [
    {
      "name": "imgui",
      "features": [
        "sdl3-binding",
        "sdl3-renderer-binding"
      ]
    },
    {
      "name": "sdl3",
      "features": [
        "vulkan"
      ]
    },
    {
      "name": "sdl3-image",
      "features": [
        "png"
      ]
    },
    "sdl3-ttf"
  ]
}

CMakeLists.txt:

cmake_minimum_required(VERSION 4.0)

project(kontrol)

set(CMAKE_CXX_STANDARD 23)
set(CMAKE_VERBOSE_MAKEFILE 1)
SET(CMAKE_BUILD_TYPE Debug)

add_executable(${PROJECT_NAME}
        src/main.cpp
        src/App.cpp
        src/App.h
)

find_package(SDL3 CONFIG REQUIRED)
target_link_libraries(${PROJECT_NAME} PRIVATE SDL3::SDL3)

find_package(SDL3_image CONFIG REQUIRED)
target_link_libraries(${PROJECT_NAME} PRIVATE $<IF:$<TARGET_EXISTS:SDL3_image::SDL3_image-shared>,SDL3_image::SDL3_image-shared,SDL3_image::SDL3_image-static>)

find_package(SDL3_ttf CONFIG REQUIRED)
target_link_libraries(${PROJECT_NAME} PRIVATE SDL3_ttf::SDL3_ttf)

find_package(imgui CONFIG REQUIRED)
target_link_libraries(${PROJECT_NAME} PRIVATE imgui::imgui)

Buid:

"G:\Program Files\JetBrains\CLion 2025.2.3\bin\cmake\win\x64\bin\cmake.exe" --build G:\Projects\Kontrol\build --target kontrol -j 14
[1/2] Building CXX object CMakeFiles/kontrol.dir/src/App.cpp.obj
[2/2] Linking CXX executable kontrol.exe
FAILED: kontrol.exe 
C:\WINDOWS\system32\cmd.exe /C "cd . && "G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin\g++.exe" -g  CMakeFiles/kontrol.dir/src/main.cpp.obj CMakeFiles/kontrol.dir/src/App.cpp.obj -o kontrol.exe -Wl,--out-implib,libkontrol.dll.a -Wl,--major-image-version,0,--minor-image-version,0  vcpkg_installed/x64-windows/debug/lib/SDL3_image.lib  vcpkg_installed/x64-windows/debug/lib/SDL3_ttf.lib  vcpkg_installed/x64-windows/debug/lib/imguid.lib  vcpkg_installed/x64-windows/debug/lib/SDL3.lib  -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 && C:\WINDOWS\system32\cmd.exe /C "cd /D G:\Projects\Kontrol\build && C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -noprofile -executionpolicy Bypass -file G:/Projects/Kontrol/vcpkg/scripts/buildsystems/msbuild/applocal.ps1 -targetBinary G:/Projects/Kontrol/build/kontrol.exe -installedDir G:/Projects/Kontrol/build/vcpkg_installed/x64-windows/debug/bin -OutVariable out""
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: CMakeFiles/kontrol.dir/src/App.cpp.obj: in function `App::Init()':
G:/Projects/Kontrol/src/App.cpp:51: undefined reference to `ImGui::DebugCheckVersionAndDataLayout(char const*, unsigned long long, unsigned long long, unsigned long long, unsigned long long, unsigned long long, unsigned long long)'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:52: undefined reference to `ImGui::CreateContext(ImFontAtlas*)'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:53: undefined reference to `ImGui::GetIO()'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:58: undefined reference to `ImGui::StyleColorsDark(ImGuiStyle*)'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:60: undefined reference to `ImGui_ImplSDL3_InitForSDLRenderer(SDL_Window*, SDL_Renderer*)'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:61: undefined reference to `ImGui_ImplSDLRenderer3_Init(SDL_Renderer*)'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: CMakeFiles/kontrol.dir/src/App.cpp.obj: in function `App::OnRender()':
G:/Projects/Kontrol/src/App.cpp:108: undefined reference to `ImGui_ImplSDLRenderer3_NewFrame()'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:109: undefined reference to `ImGui_ImplSDL3_NewFrame()'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:110: undefined reference to `ImGui::NewFrame()'
G:\Program Files\JetBrains\CLion 2025.2.3\bin\mingw\bin/ld.exe: G:/Projects/Kontrol/src/App.cpp:112: undefined reference to `ImGui::ShowDemoWindow(bool*)'
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

[ocornut]

Well then it seems like an issue with how you are using vcpkg or configuring it.