nvdec fails to allocate memory

Trying this command:

gst-launch-1.0 rtspsrc location=rtsp://.... ! rtph264depay ! h264parse ! nvdec ! fakesink

I get the error:

(gst-launch-1.0:8393): GStreamer-CRITICAL **: 17:18:48.395: gst_buffer_pool_acquire_buffer: assertion 'GST_IS_BUFFER_POOL (pool)' failed

and no video is generated at the output. Replacing nvdec with avdec_h264 works fine. Also, the NVIDIA encoder (nvh264enc) works without any issues.

The system:

• Ubuntu 16.04, headless
• gstreamer 1.15.1, compiled from source
• CUDA 10