Readme cmake example problem

[sakirma]

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The example says to use: target_link_libraries(mytarget PRIVATE box2d::box2d)

But this caused a problem when I ran the make command in the console: which showed the following problem:

And after changing the target_link_libraries to: target_link_libraries(mytarget PRIVATE box2d) It worked again

[sakirma]

This is the CMAKE if it is needed

# cmake_minimum_required(VERSION 2.6) set(CMAKE_CXX_STANDARD 17)

set(CMAKE_CURRENT_BINARY_DIR ./build) set(CMAKE_CURRENT_SOURCE_DIR ./) set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin) set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)

set(SDL2_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../SDL) set(BOX2D_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../box2d)

project(SDL2Test)

add_subdirectory(${SDL2_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR}/sdl) add_subdirectory(${BOX2D_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR}/box2d)

add_executable(SDL2Test Main.cpp)

find_package(box2d REQUIRED)

target_include_directories(SDL2Test PUBLIC ${SDL2_SOURCE_DIR}/include ${BOX2D_SOURCE_DIR}/include/box2d)

target_link_libraries(SDL2Test PRIVATE SDL2 box2d) #

I have box2D as a SubModule in my git repository

[thegrb93]

I've never seen box2d::box2d syntax before. Is it a new cmake feature? Might just be a copy-paste typo.

[sakirma]

It is on the Readme page. It doesn't work for me at least and I have the latest CMake version.

[thegrb93]

I know, I saw it there. I meant I haven't seen it anywhere else.

[sakirma]

Ah sorry, but are you able to remake this problem? With the latest CMake

[invitus]

Actually, I think the box2d::box2d example was correct if you use the box2dConfig.cmake script to find box2d.

CMakeLists.txt in src:

...
install(
  TARGETS box2d
  EXPORT box2dConfig
  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

install(
  EXPORT box2dConfig
  NAMESPACE box2d::
  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/box2d"
)
...

Due to the namespace it will hide the library behind it. Corresponding box2dConfig.cmake script from the install target:

...
# Create imported target box2d::box2d
add_library(box2d::box2d STATIC IMPORTED)
...

Using this i had to use: target_link_libraries(mytarget box2d::box2d)

Otherwise it did not find any header and can not find the box2d.lib