use std::io; use git_transport::client;use quick_error::quick_error; use crate::{    credentials,    fetch::{refs, response},}; quick_error! {    /// The error used in [`fetch()`][super::fetch].    #[derive(Debug)]    #[allow(missing_docs)]    pub enum Error {        Io(err: io::Error) {            display("Could not access repository or failed to read streaming pack file")            from()            source(err)        }        Credentials(err: credentials::helper::Error) {            display("Failed to obtain, approve or reject credentials")            from()            source(err)        }        Transport(err: client::Error) {            display("An error occurred on the transport layer while fetching data")            from()            source(err)        }        SymrefWithoutValue {            display("A symref 'capability' is expected to have a value")        }        TransportProtocolPolicyViolation{actual_version: git_transport::Protocol} {            display("The transport didn't accept the advertised server version {:?} and closed the connection client side", actual_version)        }        Ref(err: refs::Error) {            display("A reference could not be parsed or invariants were not met")            from()            source(err)        }        Response(err: response::Error) {            display("The server response could not be parsed")            from()            source(err)        }    }}