It looks like the project returned form the hiatus half a year ago, so this issue is no longer a problem for crates that use newer versions of `spin` so it's rather a matter of upgrading those in unstable after bullseye has been released.
Further information on the RustSec entry: https://github.com/RustSec/advisory-db/issues/830 https://github.com/RustSec/advisory-db/pull/423
