4.13.0-17.20~16.04.1) is not available, but a newer one is (4.13.0-45.50~16.04.1). We redirected you there.
/usr/lib/liberl_interface_st.a is in erlang-dev 1:18.3-dfsg-1ubuntu3.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/erlang/usr/lib/liberl_interface_st.a