History of checkpointer 2 changes

In crates/hub/src/tlog.rs, lines 748–765 on 4dfa4599b3f7e3d1150681fcfca0c2e459262806e6248033cc1ae9cb27de1912. 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 748,765:crates/hub/src/tlog.rs.