CasADI in C++: symbol lookup error - undefined symbol

[M R]

Hello all,

I want to include CasADI with c++ and I followed this example to include it with cmake.

https://stackoverflow.com/questions/71489173/integrate-pre-compiled-libraries-into-c-codebase-with-cmake-externalproject/71546749#71546749

I also added that flag to the CMakeLists: add_definitions(-D_GLIBCXX_USE_CXX11_ABI=0)

(from that post: https://groups.google.com/g/casadi-users/c/xIw4U6Rymps?pli=1)

I am not able to generate any CasADI symbols like SX or MX. When I add this line "SX a = SX::sym("a");" into my main.cpp I receive an error message when executing the generated exe.

I can compile my code in the build folder with 

1. cmake ..

2. make

and it compiles. When executing the executable, I am running into the following error: 

./untitled: symbol lookup error: ./untitled: undefined symbol: _ZN6casadi6MatrixINS_6SXElemEE4_symERKSsRKNS_8SparsityE

Does anybody knows a solution for that kind of problems?

Thank you very much for any help! Below is my code :)

My file structure:

• CMakeLists.txt
• main.cpp
• build
  • ... all build files
  • untitled (exe)
• external
  • CMakeLists.txt

The included code:

main.cpp:

#include <casadi/casadi.hpp>

using namespace casadi;

using namespace std;

int main()

{

casadi_printf("This works! \n");

SX a = SX::sym("a");

return 0;

}

CMakeLists.txt: 

cmake_minimum_required(VERSION 3.10)

project(untitled)

set(CMAKE_CXX_STANDARD 17)

# some default target

add_executable(untitled main.cpp)

add_definitions(-D_GLIBCXX_USE_CXX11_ABI=0)

# Configure and build external project

file(MAKE_DIRECTORY ${CMAKE_BINARY_DIR}/external)

execute_process(

COMMAND ${CMAKE_COMMAND} ${CMAKE_SOURCE_DIR}/external

WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/external

)

execute_process(

COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR}/external

)

# find and link externals

find_package(casadi REQUIRED HINTS ${CMAKE_BINARY_DIR}/external/external/casadi/src/casadi-3.5.5/casadi)

target_link_libraries(untitled casadi)

external/CMakeLists.txt:

cmake_minimum_required(VERSION 3.10)

project(external)

add_definitions(-D_GLIBCXX_USE_CXX11_ABI=0)

include(ExternalProject)

ExternalProject_Add(

casadi-3.5.5

URL https://github.com/casadi/casadi/releases/download/3.5.5/casadi-linux-py39-v3.5.5-64bit.tar.gz

CONFIGURE_COMMAND ""

BUILD_COMMAND ""

INSTALL_COMMAND ""

PREFIX ${CMAKE_BINARY_DIR}/external/casadi)