use crate::pack;use quick_error::quick_error;use std::io; quick_error! {    #[derive(Debug)]    pub enum Error {        Io(err: io::Error) {            display("An IO error occurred when reading the pack or creating a temporary file")            from()            source(err)        }        PackEntryDecode(err: pack::data::iter::Error) {            display("A pack entry could not be extracted")            from()            source(err)        }        Unsupported(kind: pack::index::Kind) {            display("Indices of type {} cannot be written, only {} are supported", *kind as usize, pack::index::Kind::default() as usize)        }        IteratorInvariantNoRefDelta {            display("Ref delta objects are not supported as there is no way to look them up. Resolve them beforehand.")        }        IteratorInvariantTrailer {            display("The iterator failed to set a trailing hash over all prior pack entries in the last provided entry")        }        IteratorInvariantBasesPresent {            display("Did not encounter a single base")        }        IteratorInvariantTooManyObjects(num_objects: usize) {            display("Only u32::MAX objects can be stored in a pack, found {}", num_objects)        }        IteratorInvariantBaseOffset(pack_offset: u64, distance: u64) {            display("{} is not a valid offset for pack offset {}", distance, pack_offset)        }        Tree(err: pack::tree::Error) {            display("An invariant regarding the delta tree did not hold")            source(err)            from()        }        TreeTraversal(err: pack::tree::traverse::Error) {            display("Tree traversal failed")            source(err)            from()        }    }}