rocksdb error when stopping node: pure virtual method called

[tmpolaczyk]

Sometimes after pressing ctrl-c to stop the node, you can see this message:

pure virtual method called
terminate called without an active exception

This is probably because rocksdb doesn't have enough time to clean up. Adding a sleep(500ms) to impl Drop for StorageManager seems to mitigate the issue. I tried updating the version of the rocksdb crate to 0.16.0 and the problem still exists.

As far as I know there aren't any corruption problems related to this log, so low priority.

[tmpolaczyk]

This error can still be seen in some cases, for example if the node panics right after starting (for example when it's missing a genesis_block.json file or if the port 21337 is already used by another process).

[tmpolaczyk]

This error still happens as of commit 18246db9f737e377b58b34746e288600d2454457, a simple way to reproduce it is to start a node and quickly press ctrl-c to stop it.