/usr/lib/libguilereadline-v-18.so.18 is in guile-2.0-libs 2.0.9+1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libguilereadline-v-18.so.18.0.0
/usr/lib/libguilereadline-v-18.so.18.0.0