gr-fosphor install troubles:" Unable to share spectrum VBO into OpenCL context" openCL/GL sharing

I compared fosphor to the nVidia OpenCL Simple OpenGL Interop example [1] and noticed that fosphor calls glMapBuffer/glUnmapBuffer to clear the spectrum vbo between the calls to glBufferData and clCreateFromGLBuffer. If I eliminate the map/memset/unmap here by removing the call to gl_vbo_clear in gl_deferred_init [2], then clCreateFromGLBuffer returns CL_SUCCESS and fosphor appears to work with CL/GL sharing. It is not clear to me if clearing the vbo_spectrum is necessary here, since cl_queue_clear_buffers later initializes the mem_spectrum buffer to the noise floor. I'm using an nvidia GTX 1650 with version 430.50 of the nvidia drivers under Linux Mint 18. A friend of mine tested the GTX 1060 and also had success with this workaround. Aaron [1] http://developer.download.nvidia.com/compute/DevZone/OpenCL/Projects/oclSim… [2] https://git.osmocom.org/gr-fosphor/tree/lib/fosphor/gl.c#n235