Segmentation fault when using nmos-cpp through conan package

[thomasdethier]

Hello,

I am currently developping a C++ application using the nmos-cpp conan package. I did a really simple node-implementation just to test that my node is up and can connect to my registry.

When I try to run my application I get a segmentation fault at the node server start (when I call node_server.open().wait();). It seems it comes from cpp-rest.

To quickly check if my code was responsible for this error, I've tried running the nmos-cpp node example present in the official repo with the conan package. I was surprised to also get a segmentation fault. I didn't have the error when running the node implementation example with directly using nmos-cpp source code and not the conan package.

Is the conan package still up to date with the official node implementation ? Is this a known bug ?

If you need more context, I'll be happy to provide any information that should be required.

[dk-macnica]

Hello,

I'm seeing the same issue in nmos-cpp-node. The weird thing is that this problem is present only under new ubuntu users, it works fine under users which existed for a long time (and under which nmos node has been run before). It looks like some conan package got updated, so when conan downloads it from scratch nmos-cpp-node starts to fail in Debug and freezes in Release mode.

Here is full backtrace of segmentation fault:

#0  0x00005555556d5d2f in boost::asio::detail::op_queue_access::next<boost::asio::detail::scheduler_operation, boost::asio::detail::scheduler_operation> (
    o1=@0x5555567dddf8: 0x2800000000, o2=0x5555569a8440)
    at /home/testuser/.conan/data/boost/1.80.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/detail/op_queue.hpp:41
#1  0x00005555556ce453 in boost::asio::detail::op_queue<boost::asio::detail::scheduler_operation>::push (this=0x5555567dddf0, h=0x5555569a8440)
    at /home/testuser/.conan/data/boost/1.80.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/detail/op_queue.hpp:110
#2  0x00005555556b78ae in boost::asio::detail::scheduler::post_immediate_completion (this=0x5555567ddd10, op=0x5555569a8440, is_continuation=false)
    at /home/testuser/.conan/data/boost/1.80.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/detail/impl/scheduler.ipp:364
#3  0x0000555555db7168 in boost::asio::io_context::initiate_post::operator()<boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > > > (
    this=0x7fffffffce4f, handler=..., self=0x555556794b68 <(anonymous namespace)::initialize_shared_threadpool(unsigned long)::uninit_threadpool+8>)
    at /home/conan/w/BuildSingleReference/.conan/data/boost/1.76.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/impl/io_context.hpp:191
#4  0x0000555555db7078 in boost::asio::async_result<boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > >, void ()>::initiate<boost::asio::io_context::initiate_post, boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > >, boost::asio::io_context*>(boost::asio::io_context::initiate_post&&, boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > >&&, boost::asio::io_context*&&) (initiation=..., token=..., 
    args#0=@0x7fffffffce50: 0x555556794b68 <(anonymous namespace)::initialize_shared_threadpool(unsigned long)::uninit_threadpool+8>)
    at /home/conan/w/BuildSingleReference/.conan/data/boost/1.76.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/async_result.hpp:152
#5  0x0000555555db7024 in boost::asio::async_initiate<boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > >, void (), boost::asio::io_context::initiate_post, boost::asio::io_context*>(boost::asio::io_context::initiate_post&&, boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > >&, boost::asio::io_context*&&) (initiation=..., token=..., args#0=@0x7fffffffce50: 0x555556794b68 <(anonymous namespace)::initialize_shared_threadpool(unsigned long)::uninit_threadpool+8>)
    at /home/conan/w/BuildSingleReference/.conan/data/boost/1.76.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/async_result.hpp:365
#6  0x0000555555db6f60 in boost::asio::io_context::post<boost::_bi::bind_t<void, void (*)(void*), boost::_bi::list1<boost::_bi::value<void*> > > > (
    this=0x555556794b68 <(anonymous namespace)::initialize_shared_threadpool(unsigned long)::uninit_threadpool+8>, handler=...)
    at /home/conan/w/BuildSingleReference/.conan/data/boost/1.76.0/_/_/package/a77ca77d437f4354bdec12173c1a0c2b8b7d01f4/include/boost/asio/impl/io_context.hpp:200
#7  0x0000555555db6b76 in pplx::details::linux_scheduler::schedule (this=0x55555693a190, proc=0x5555556545c1 <pplx::details::_TaskProcHandle::_RunChoreBridge(void*)>, 
    param=0x5555569c1780)
    at /home/conan/w/BuildSingleReference/.conan/data/cpprestsdk/2.10.18/_/_/build/cf242e70f5ea369f0e64dae39424b17c2e0664d7/source_subfolder/Release/src/pplx/pplxlinux.cpp:38
#8  0x00005555556547ab in pplx::details::_TaskCollectionImpl::_ScheduleTask (this=0x55555694ade0, _PTaskHandle=0x5555569c1780, _InliningMode=pplx::details::_NoInline)
    at /home/testuser/.conan/data/cpprestsdk/2.10.18/_/_/package/cf242e70f5ea369f0e64dae39424b17c2e0664d7/include/pplx/pplx.h:146
#9  0x000055555565562f in pplx::details::_Task_impl_base::_ScheduleTask (this=0x55555694ad80, _PTaskHandle=0x5555569c1780, _InliningMode=pplx::details::_NoInline)
    at /home/testuser/.conan/data/cpprestsdk/2.10.18/_/_/package/cf242e70f5ea369f0e64dae39424b17c2e0664d7/include/pplx/pplxtasks.h:1964
#10 0x00005555559f5c21 in pplx::task<unsigned char>::_TaskInitWithFunctor<void, nmos::server::open()::<lambda()> >(const nmos::server::<lambda()> &) (this=0x7fffffffd0d0, 
    _Func=...) at /home/testuser/.conan/data/cpprestsdk/2.10.18/_/_/package/cf242e70f5ea369f0e64dae39424b17c2e0664d7/include/pplx/pplxtasks.h:4155
#11 0x00005555559f5699 in pplx::task<void>::_TaskInitMaybeFunctor<nmos::server::open()::<lambda()> >(nmos::server::<lambda()> &, std::true_type) (this=0x7fffffffd0d0, _Func=...)
    at /home/testuser/.conan/data/cpprestsdk/2.10.18/_/_/package/cf242e70f5ea369f0e64dae39424b17c2e0664d7/include/pplx/pplxtasks.h:4755
#12 0x00005555559f4cab in pplx::task<void>::task<nmos::server::open()::<lambda()> >(nmos::server::<lambda()>, const pplx::task_options &) (this=0x7fffffffd0d0, _Param=..., 
    _TaskOptions=...) at /home/testuser/.conan/data/cpprestsdk/2.10.18/_/_/package/cf242e70f5ea369f0e64dae39424b17c2e0664d7/include/pplx/pplxtasks.h:4408
#13 0x00005555559f4816 in pplx::create_task<nmos::server::open()::<lambda()> >(nmos::server::<lambda()>, pplx::task_options) (_Param=..., _TaskOptions=...)
    at /home/testuser/.conan/data/cpprestsdk/2.10.18/_/_/package/cf242e70f5ea369f0e64dae39424b17c2e0664d7/include/pplx/pplxtasks.h:4886
#14 0x00005555559f3b74 in nmos::server::open (this=0x7fffffffd280) at /home/testuser/nmos-cpp/Development/nmos/server.cpp:12
#15 0x000055555560085f in pplx::open_close_guard<nmos::server>::open_close_guard (this=0x7fffffffd230, t=...) at /home/testuser/nmos-cpp/Development/pplx/pplx_utils.h:255
#16 0x00005555555e5fb9 in main (argc=1, argv=0x7fffffffe3b8) at /home/testuser/nmos-cpp/Development/nmos-cpp-node/main.cpp:143

Temporary fix which worked out for me:
Removed ~/.conan directory under new user and copied ~/.conan from working user. Then after rebuild nmos-cpp-node started working for new ubuntu user.

[garethsb]

A Conan Center Index maintainer frustratingly removed the recipe requirement that the same Boost minor version is used between nmos-cpp and cpprestsdk. Boost does not keep binary compatibility between minor versions and that is known to cause the issue you are seeing. conan-io/conan-center-index#17096 (comment)

Please confirm the versions and recipe revisions you are using of Conan itself, nmos-cpp, cpprestsdk, Boost and other dependencies.

A possible workaround is to force Conan to build all packages locally, though this significantly reduces the benefit of using Conan.

[garethsb]

I now recommend adopting Conan 2 which is better able to express the nuances of dependencies. There is also a new conan package nmos-cpp/cci.20240223.