/usr/lib/x86_64-linux-gnu/libunwind-generic.a is in libunwind8-dev 1.1-2.2ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libunwind-x86_64.a
/usr/lib/x86_64-linux-gnu/libunwind-x86_64.a