Perhaps somebody has a better explanation of whats going on for such a simple thing.
Its ubuntu 21.10, and repo has gnuradio-3.8.2 and uhd-3.15, thats ok the version i need (although if somebody wants 3.9 maybe a problem with Release file)
/usr/bin/uhd_image_loader
put the images into /usr/share/uhd/images
uhd_config_info --print-all
shows Images directory as nothing (no path)
after i set environment variable
export UHD_IMAGES_DIR=/usr/share/uhd/images
then uhd_usrp_probe downloads firmware and shows my B100 correctly, all OK after setting this environment var.