[BUG] Error linking to Conan-installed Boost

I am probably doing something wrong, because I'm very new to C++ and wanted to start from a sensible template. (This template is awesome, by the way! It got me started very well, and I am much happier with the state of my learning project than I could imagine if I started from scratch. I just like myself a good build/package structure.)

Describe the bug

Following the instructions, I had a Conan provided library not linked, so I got undefined reference to boost::read_graphml(std::istream&, boost::mutate_graph&, unsigned long)' from ld.

To Reproduce Steps to reproduce the behavior:

I am trying to play around with graphs, so I included Conan in the cmake configuration

option(${PROJECT_NAME}_ENABLE_CONAN "Enable the Conan package manager for this project." ON)

and changed the Conan.cmake to include boost

  set(${PROJECT_NAME}_CONAN_REQUIRES "boost/1.79.0")

I set the project to compile executables and wrote a small main.cpp to load a graph from a GraphML file

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graph_concepts.hpp>
#include <boost/graph/graphml.hpp>
#include <ios>
#include <list>

#include "cmcmc/tmp.hpp"

using namespace std;

int main(int argc, char *argv[])
{
  using Graph = boost::adjacency_list<>;
  Graph g;
  boost::dynamic_properties dp{ boost::ignore_other_properties };

  if (argc > 1)
  {
    ifstream in{ argv[1] };
    boost::read_graphml(in, g, dp, 0);
  }
}

:boom:

/usr/bin/ld: CMakeFiles/CMCMC.dir/src/main.cpp.o: in function `void boost::read_graphml<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::no_property, boost::no_property, boost::no_property, boost::listS> >(std::istream&, boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::no_property, boost::no_property, boost::no_property, boost::listS>&, boost::dynamic_properties&, unsigned long)':
/home/anaphory/.conan/data/boost/1.79.0/_/_/package/1671931156455a119d7c3f14d951ac5fdbc5cd10/include/boost/graph/graphml.hpp:229: undefined reference to `boost::read_graphml(std::istream&, boost::mutate_graph&, unsigned long)'
collect2: error: ld returned 1 exit status

Expected behavior

I thought with this setup, Conan would pull in Boost to a known location, and cmake would ensure it gets linked to. (I had some version of Boost headers available before installing Boost using Conan, so that may have complicated the impression I got.)

Workaround

I added conan_target_link_libraries(${PROJECT_NAME}) as last line to my CMakeList.txt and it works fine. So I assume the issue is more how I use the template and associated software – which, fair, I don't really understand well enough – and not an actual issue with the template, but maybe it is an issue worth pointing out?

Environment

I'm happy to provide version strings and other similar items, I just don't know what is useful.

filipdutescu / modern-cpp-template

[BUG] Error linking to Conan-installed Boost #40