/usr/lib/libtcmalloc_minimal_debug.so.4 is in libtcmalloc-minimal4 2.1-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libtcmalloc_minimal_debug.so.4.1.2
/usr/lib/libtcmalloc_minimal_debug.so.4.1.2