History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 49–51 on 34beb1a7e37689fe3ebcff9b8a63e5f900047cbb38793e4d2bbf0324bc6c6bae. 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 49,51:crates/hub/src/protocol.rs.