Error while building example: takeoff_and_land

[shakthi-prashanth-m]

Hi Julian, I did build DroneLink as mentioned. I wanted to try running example. Got below error.
Could you please check ?

~/DroneLink/example$ make
[  3%] Built target gtest
[  6%] Built target gtest_main
[ 56%] Built target dronelink
[ 57%] Building CXX object CMakeFiles/integration_tests_runner.dir/integration_tests/curl.cpp.o
/home/shakthi/DroneLink/integration_tests/curl.cpp:10:25: error: ‘testing’ has not been declared
 class CurlTest : public testing::Test
                         ^
/home/shakthi/DroneLink/integration_tests/curl.cpp:10:34: error: expected ‘{’ before ‘Test’
 class CurlTest : public testing::Test
                                  ^
/home/shakthi/DroneLink/integration_tests/curl.cpp:12:1: error: expected primary-expression before ‘protected’
 protected:
 ^
/home/shakthi/DroneLink/integration_tests/curl.cpp:12:1: error: expected ‘}’ before ‘protected’
/home/shakthi/DroneLink/integration_tests/curl.cpp:12:1: error: expected ‘,’ or ‘;’ before ‘protected’
/home/shakthi/DroneLink/integration_tests/curl.cpp:18:24: error: ‘virtual’ outside class declaration
     virtual void SetUp()
                        ^
/home/shakthi/DroneLink/integration_tests/curl.cpp: In function ‘void SetUp()’:
/home/shakthi/DroneLink/integration_tests/curl.cpp:20:15: error: ‘clean’ was not declared in this scope
         clean();
               ^
/home/shakthi/DroneLink/integration_tests/curl.cpp:21:9: error: ‘_file_url_existing_http’ was not declared in this scope
         _file_url_existing_http =
         ^
/home/shakthi/DroneLink/integration_tests/curl.cpp: At global scope:
/home/shakthi/DroneLink/integration_tests/curl.cpp:29:27: error: ‘virtual’ outside class declaration
     virtual void TearDown()
                           ^
/home/shakthi/DroneLink/integration_tests/curl.cpp: In function ‘void TearDown()’:
/home/shakthi/DroneLink/integration_tests/curl.cpp:31:15: error: ‘clean’ was not declared in this scope
         clean();
               ^
/home/shakthi/DroneLink/integration_tests/curl.cpp: At global scope:
/home/shakthi/DroneLink/integration_tests/curl.cpp:45:1: error: expected declaration before ‘}’ token
 };
 ^
CMakeFiles/integration_tests_runner.dir/build.make:422: recipe for target 'CMakeFiles/integration_tests_runner.dir/integration_tests/curl.cpp.o' failed
make[2]: *** [CMakeFiles/integration_tests_runner.dir/integration_tests/curl.cpp.o] Error 1
CMakeFiles/Makefile2:69: recipe for target 'CMakeFiles/integration_tests_runner.dir/all' failed
make[1]: *** [CMakeFiles/integration_tests_runner.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2

Thanks

[julianoes]

It looks like you are not following the exact instructions to compile the example, can you please follow again the steps written in https://github.com/PX4/DroneLink#example.

[shakthi-prashanth-m]

Hi Julian, thanks for the comment. make default install was missing before. So build failed.

I get below linker error. libdronlink.a doesn't seem to be linked pthread library.

Scanning dependencies of target takeoff_and_land
[ 50%] Linking CXX executable takeoff_and_land
../install/lib/libdronelink.a(udp_connection.cpp.o): In function `std::thread::thread<void (&)(dronelink::UdpConnection*), dronelink::UdpConnection*>(void (&)(dronelink::UdpConnection*), dronelink::UdpConnection*&&)':
udp_connection.cpp:(.text._ZNSt6threadC2IRFvPN9dronelink13UdpConnectionEEJS3_EEEOT_DpOT0_[_ZNSt6threadC5IRFvPN9dronelink13UdpConnectionEEJS3_EEEOT_DpOT0_]+0x93): undefined reference to `pthread_create'
../install/lib/libdronelink.a(device_impl.cpp.o): In function `std::thread::thread<void (&)(dronelink::DeviceImpl*), dronelink::DeviceImpl*>(void (&)(dronelink::DeviceImpl*), dronelink::DeviceImpl*&&)':
device_impl.cpp:(.text._ZNSt6threadC2IRFvPN9dronelink10DeviceImplEEJS3_EEEOT_DpOT0_[_ZNSt6threadC5IRFvPN9dronelink10DeviceImplEEJS3_EEEOT_DpOT0_]+0x93): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/takeoff_and_land.dir/build.make:95: recipe for target 'takeoff_and_land' failed
make[2]: *** [takeoff_and_land] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/takeoff_and_land.dir/all' failed
make[1]: *** [CMakeFiles/takeoff_and_land.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2

After making these changes, it is built successfully.

Kindly check.
Thanks

[julianoes]

@shakthi-prashanth-m strange, do you follow exactly these steps?

cd example/
mkdir build && cd build
cmake ..
make && ./takeoff_and_land

[shakthi-prashanth-m]

Yes. Please find attachment.

[julianoes]

Ok thanks, I'm able to reproduce it.