Hello, I'm creating a GNU Radio OOT module in C++ language, in which I instantiate an osmosdr source. The syntax is : osmosdr::source ::sptr m_source = osmosdr::source::make(); I also implement other blocks in my design. In CMakeLists.txt file, I specify all these components: set(GR_REQUIRED_COMPONENTS RUNTIME BLOCKS FFT OSMOSDR) find_package(Gnuradio-osdmosdr REQUIRED) include_directories( ... ${GNURADIO_OSMOSDR_INCLUDE_DIRS} ) link_directories( ... ${GNURADIO_OSMOSDR_LIBRARY_DIRS} ) In cmake/Modules folder, I copied the FindGnuradio-osmosdr.cmake file from gqrx project. The logs of cmake command show that the osmosdr library is found: -- checking for module 'gnuradio-osmosdr' -- Found gnuradio-osmosdr, version v0.1.4-127-g4d83c606 -- Found GNURADIO_OSMOSDR: /usr/local/lib/libgnuradio-osmosdr.so After compiling the module (cmake .. -> make -> make install -> ldconfig), I got the error 'AttributeError: 'module' object has no attribute 'test'. I analysed the undefined symbol, and it was due to osmosdr module. Any suggestion to solve this problem? PS: - I'm working on Ubuntu 16.04 (VM), gnuradio 3.7.9, cmake 3.5.1 - In GRC, the osmosdr source and sink work fine Thanks.