Okay, so I removed (string) part from your code and now it gives this error
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.155: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideosink.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideosink.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.156: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvivafilter.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvivafilter.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.156: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnveglglessink.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnveglglessink.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.157: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstomx.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstomx.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.157: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvdrmvideosink.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvdrmvideosink.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.157: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvidconv.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvidconv.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.158: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvtee.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvtee.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.158: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvv4l2camerasrc.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvv4l2camerasrc.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.159: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideo4linux2.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideo4linux2.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.159: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvegltransform.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvegltransform.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.159: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnveglstreamsrc.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnveglstreamsrc.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.159: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideosinks.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideosinks.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.160: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvarguscamerasrc.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvarguscamerasrc.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.160: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvjpeg.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvjpeg.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.160: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideocuda.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvvideocuda.so: file too short
(gst-plugin-scanner:264): GStreamer-WARNING **: 18:47:26.161: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvcompositor.so': /usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstnvcompositor.so: file too short
which is weird so I check with ldconfig and it gives this error
ldconfig
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libv4lconvert.so.0.0.999999 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libv4l2.so.0.0.999999 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_calib3d.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_flann.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_imgcodecs.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_core.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_gapi.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_imgproc.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_dnn.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_features2d.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_ml.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_dnn.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_photo.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_stitching.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_highgui.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_gapi.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_video.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_objdetect.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_videoio.so.4.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_imgproc.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_highgui.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_photo.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_flann.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_features2d.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libgstnvivameta.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_gapi.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_core.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libnvsample_cudaprocess.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_imgcodecs.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_ml.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_stitching.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_videoio.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_dnn.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_calib3d.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_video.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libgstnvegl-1.0.so.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libgstnvexifmeta.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/libopencv_objdetect.so.4.1.1 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvdecode2eglimage.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvexif.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvofsdk.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvtracebuf.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvapputil.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcuvidv4l2.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvid_mapper.so.1.0.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvodm_imager.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvavp.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvid_mapper.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnveglstream_camconsumer.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcam_imageencoder.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvbufsurface.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcameratools.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmm.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcapture.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libtegrav4l2.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libv4l2_nvcuvidvideocodec.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvtvmr.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvbufsurftransform.so.1.0.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvtestresults.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmm_contentpipe.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvomxilclient.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmmlite_utils.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcamv4l2.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvargus.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvargus_socketserver.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvtnr.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libv4l2_nvvideocodec.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnveventlib.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvomx.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmm_parser.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmmlite_video.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnveglstreamproducer.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvscf.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvosd.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libv4l2.so.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvargus_socketclient.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvbufsurftransform.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmm_utils.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libv4l2_nvvidconv.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvdsbufferpool.so.1.0.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvbufsurface.so.1.0.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvjpeg.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvv4lconvert.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcamlog.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvcamerautils.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvv4l2.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmedia.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmmlite_image.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libv4l2_nvargus.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libv4lconvert.so.0 is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvparser.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvmmlite.so is empty, not checked.
/sbin/ldconfig.real: File /usr/lib/aarch64-linux-gnu/tegra/libnvdsbufferpool.so is empty, not checked.
Seems like the build is broken somehow?
I followed instruction here though (although I did it in docker)