Standalone Asio not found - but asio.hpp is present about simple-websocket-server

[galeone]

The problem is in pthread linking, it looks like your CMake file (when using CHECK_INCLUDE_FILE_CXX(asio.hpp)) does not link against pthread

Determining if the include file asio.hpp exists failed with the following output:
Change Dir: /tmp/Simple-WebSocket-Server/build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_1b98a/fast"
/usr/bin/make -f CMakeFiles/cmTC_1b98a.dir/build.make CMakeFiles/cmTC_1b98a.dir/build
make[1]: Entering directory '/tmp/Simple-WebSocket-Server/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_1b98a.dir/CheckIncludeFile.cxx.o
/usr/bin/c++     -o CMakeFiles/cmTC_1b98a.dir/CheckIncludeFile.cxx.o -c /tmp/Simple-WebSocket-Server/build/CMakeFiles/CMakeTmp/CheckIncludeFile.cxx
Linking CXX executable cmTC_1b98a
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_1b98a.dir/link.txt --verbose=1
/usr/bin/c++       -rdynamic CMakeFiles/cmTC_1b98a.dir/CheckIncludeFile.cxx.o  -o cmTC_1b98a 
CMakeFiles/cmTC_1b98a.dir/CheckIncludeFile.cxx.o: In function `asio::detail::posix_thread::~posix_thread()':
CheckIncludeFile.cxx:(.text._ZN4asio6detail12posix_threadD2Ev[_ZN4asio6detail12posix_threadD5Ev]+0x26): undefined reference to `pthread_detach'
CMakeFiles/cmTC_1b98a.dir/CheckIncludeFile.cxx.o: In function `asio::detail::posix_thread::join()':
CheckIncludeFile.cxx:(.text._ZN4asio6detail12posix_thread4joinEv[_ZN4asio6detail12posix_thread4joinEv]+0x2b): undefined reference to `pthread_join'
collect2: error: ld returned 1 exit status
make[1]: *** [CMakeFiles/cmTC_1b98a.dir/build.make:98: cmTC_1b98a] Error 1
make[1]: Leaving directory '/tmp/Simple-WebSocket-Server/build/CMakeFiles/CMakeTmp'
make: *** [Makefile:126: cmTC_1b98a/fast] Error 2

[eidheim]

pthread linking should be added here: https://github.com/eidheim/Simple-WebSocket-Server/blob/master/CMakeLists.txt#L19 if needed.

[eidheim]

This seems to be a problem with cmake's CheckIncludeFileCXX though. I just confirmed this issue on Antergos. Temporary workaround:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2b0ea16..8f31cb5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,11 +22,6 @@ target_link_libraries(simple-websocket-server INTERFACE ${CMAKE_THREAD_LIBS_INIT
 # Remove Boost system, thread, regex components; use Boost::<component> aliases; remove Boost target_include_directories
 if(USE_STANDALONE_ASIO)
     target_compile_definitions(simple-websocket-server INTERFACE USE_STANDALONE_ASIO)
-    include(CheckIncludeFileCXX)
-    CHECK_INCLUDE_FILE_CXX(asio.hpp HAVE_ASIO)
-    if(NOT HAVE_ASIO)
-        message(FATAL_ERROR "Standalone Asio not found")
-    endif()
 else()
     find_package(Boost 1.54.0 COMPONENTS system thread coroutine context REQUIRED)
     target_link_libraries(simple-websocket-server INTERFACE ${Boost_LIBRARIES})

[galeone]

Yeah, I ended up with the same workaround (although it should be temporary for sure since we're not checking if asio.hpp is present hence the compilation can start and fail if the library is not present for real).