According to its documentation its specifically tailed down to deliver everything for rust backtrace crate:
https://packages.debian.org/buster/librust-backtrace+libbacktrace-dev
The official requierement would be install `cc` and `ar`, where `ar` is in binutils, and `cc` seems to be in gcc-8 or a subpackage of it. Both would requiere about 100MB additionally for backtraces, while this package should requiere additional 8MB