/usr/lib/x86_64-linux-gnu/libsingular-resources.so is in libsingular4-dev 4.0.3+ds-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libsingular-resources-4.0.3.so
/usr/lib/x86_64-linux-gnu/libsingular-resources-4.0.3.so