[INFO] updating cached repository https://github.com/maelvalais/rust-chat
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b9699a21ff4f0883954f6e9a291e81787a0daee3
[INFO] checking maelvalais/rust-chat against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmaelvalais%2Frust-chat" "work/builds/worker-4/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/maelvalais/rust-chat on toolchain c9edc02e8320a9e5799d185910ece7d491f524e6-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/maelvalais/rust-chat
[INFO] finished tweaking git repo https://github.com/maelvalais/rust-chat
[INFO] tweaked toml for git repo https://github.com/maelvalais/rust-chat written to work/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/maelvalais/rust-chat already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/mnt/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 74cbfb400ae2a678374d6453b435ac3dd5fbce08fef4a55a7f5c9b097e3b88c7
[INFO] running `"docker" "start" "-a" "74cbfb400ae2a678374d6453b435ac3dd5fbce08fef4a55a7f5c9b097e3b88c7"`
[INFO] [stderr]     Checking error-chain v0.11.0
[INFO] [stderr]     Checking rust-chat v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:96:27
[INFO] [stderr]    |
[INFO] [stderr] 96 |         let (reader_send, mut to_main_writer) = mpsc::channel();
[INFO] [stderr]    |                           ----^^^^^^^^^^^^^^
[INFO] [stderr]    |                           |
[INFO] [stderr]    |                           help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:145:15
[INFO] [stderr]     |
[INFO] [stderr] 145 |           let mut reader: TcpStream = writer.try_clone().unwrap();
[INFO] [stderr]     |               ----^^^^^^
[INFO] [stderr]     |               |
[INFO] [stderr]     |               help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:197:13
[INFO] [stderr]     |
[INFO] [stderr] 197 |         let mut reader = TcpStream::connect(format!("{}:{}", address, port)).chain_err(|| {
[INFO] [stderr]     |             ----^^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:96:27
[INFO] [stderr]    |
[INFO] [stderr] 96 |         let (reader_send, mut to_main_writer) = mpsc::channel();
[INFO] [stderr]    |                           ----^^^^^^^^^^^^^^
[INFO] [stderr]    |                           |
[INFO] [stderr]    |                           help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:145:15
[INFO] [stderr]     |
[INFO] [stderr] 145 |           let mut reader: TcpStream = writer.try_clone().unwrap();
[INFO] [stderr]     |               ----^^^^^^
[INFO] [stderr]     |               |
[INFO] [stderr]     |               help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:197:13
[INFO] [stderr]     |
[INFO] [stderr] 197 |         let mut reader = TcpStream::connect(format!("{}:{}", address, port)).chain_err(|| {
[INFO] [stderr]     |             ----^^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.25s
[INFO] running `"docker" "inspect" "74cbfb400ae2a678374d6453b435ac3dd5fbce08fef4a55a7f5c9b097e3b88c7"`
[INFO] running `"docker" "rm" "-f" "74cbfb400ae2a678374d6453b435ac3dd5fbce08fef4a55a7f5c9b097e3b88c7"`
[INFO] [stdout] 74cbfb400ae2a678374d6453b435ac3dd5fbce08fef4a55a7f5c9b097e3b88c7