History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 68–70 on 2c47eecfeab69e364c03b79523eaeb3e72145307b46e8b0b36feaf30ae2713d5. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 68,70:crates/hub/src/protocol.rs.