After installing libiio and the test tool:

The problem is I added entries in_accel_flag and in_accel_id in the ring scan_elements directory: however, these are not part of modifier_names[] in channels.cc, so local.c (add_channel()) does not properly create the channel objct (name is "accel" instead of "accel_flag" and attributes "en" becomes "flag_en" and we fail iio_info.

Once cros_ec_ring is removed, iio_info works as expected.