History of JobGroup::drop 1 change

In crates/flow/src/syscall.rs, lines 459–468 on 06a4c472b385a86d927329debd9dac71a432292c516682b20ad73af06849e7dd. 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 459,468:crates/flow/src/syscall.rs.