History of checkpointer 2 changes

In crates/hub/src/tlog.rs, lines 748–765 on 794ff94f194a4de38bbbd80498747a270cf8ced1f95e4decc09be5cff5fca18a. 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.