[INFO] cloning repository https://github.com/Patapum/delaystderr
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Patapum/delaystderr" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FPatapum%2Fdelaystderr", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FPatapum%2Fdelaystderr'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f92d72c0c18222096e8bd72b03d961b154499efc
[INFO] testing Patapum/delaystderr against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FPatapum%2Fdelaystderr" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Patapum/delaystderr on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Patapum/delaystderr
[INFO] finished tweaking git repo https://github.com/Patapum/delaystderr
[INFO] tweaked toml for git repo https://github.com/Patapum/delaystderr written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/Patapum/delaystderr already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4d20d3477da1686ceaf5946916612e6a2aa382dc15017da3789b1c44999bf752
[INFO] running `Command { std: "docker" "start" "-a" "4d20d3477da1686ceaf5946916612e6a2aa382dc15017da3789b1c44999bf752", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4d20d3477da1686ceaf5946916612e6a2aa382dc15017da3789b1c44999bf752", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4d20d3477da1686ceaf5946916612e6a2aa382dc15017da3789b1c44999bf752", kill_on_drop: false }`
[INFO] [stdout] 4d20d3477da1686ceaf5946916612e6a2aa382dc15017da3789b1c44999bf752
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6611b722f80dc4f0e77d782ab41fd21e3359a6ec2eead5a090ad6f32b10897e2
[INFO] running `Command { std: "docker" "start" "-a" "6611b722f80dc4f0e77d782ab41fd21e3359a6ec2eead5a090ad6f32b10897e2", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.40
[INFO] [stderr]    Compiling cfg-if v0.1.3
[INFO] [stderr]    Compiling futures v0.1.21
[INFO] [stderr]    Compiling byteorder v1.2.3
[INFO] [stderr]    Compiling either v1.5.0
[INFO] [stderr]    Compiling log v0.4.1
[INFO] [stderr]    Compiling crossbeam-utils v0.3.2
[INFO] [stderr]    Compiling futures-core v0.2.1
[INFO] [stderr]    Compiling crossbeam-epoch v0.4.1
[INFO] [stderr]    Compiling futures-channel v0.2.1
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling num_cpus v1.8.0
[INFO] [stderr]    Compiling net2 v0.2.32
[INFO] [stderr]    Compiling rand v0.4.2
[INFO] [stderr]    Compiling crossbeam-deque v0.3.1
[INFO] [stderr]    Compiling bytes v0.4.7
[INFO] [stderr]    Compiling futures-io v0.2.1
[INFO] [stderr]    Compiling futures-sink v0.2.1
[INFO] [stderr]    Compiling mio v0.6.14
[INFO] [stderr]    Compiling futures-util v0.2.1
[INFO] [stderr]    Compiling mio-uds v0.6.6
[INFO] [stderr]    Compiling tokio-executor v0.1.2
[INFO] [stderr]    Compiling tokio-io v0.1.6
[INFO] [stderr]    Compiling tokio-threadpool v0.1.3
[INFO] [stderr]    Compiling tokio-timer v0.2.3
[INFO] [stderr]    Compiling futures-executor v0.2.1
[INFO] [stderr]    Compiling tokio-reactor v0.1.1
[INFO] [stderr]    Compiling futures-stable v0.2.1
[INFO] [stderr]    Compiling tokio-udp v0.1.0
[INFO] [stderr]    Compiling tokio-tcp v0.1.0
[INFO] [stderr]    Compiling tokio-fs v0.1.0
[INFO] [stderr]    Compiling futures-async-runtime v0.2.1
[INFO] [stderr]    Compiling futures v0.2.1
[INFO] [stderr]    Compiling tokio v0.1.6
[INFO] [stderr]    Compiling tokio-core v0.1.17
[INFO] [stderr]    Compiling tokio-signal v0.1.5
[INFO] [stderr]    Compiling tokio-process v0.1.6
[INFO] [stderr]    Compiling delaystderr v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(io)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::Read`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::Read;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `chars` found for mutable reference `&mut ChildStderr` in the current scope
[INFO] [stdout]   --> src/main.rs:26:46
[INFO] [stdout]    |
[INFO] [stdout] 26 |     for char in cmd.stderr.as_mut().unwrap().chars() {
[INFO] [stdout]    |                                              ^^^^^ method not found in `&mut ChildStderr`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `delaystderr` due to 3 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "6611b722f80dc4f0e77d782ab41fd21e3359a6ec2eead5a090ad6f32b10897e2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6611b722f80dc4f0e77d782ab41fd21e3359a6ec2eead5a090ad6f32b10897e2", kill_on_drop: false }`
[INFO] [stdout] 6611b722f80dc4f0e77d782ab41fd21e3359a6ec2eead5a090ad6f32b10897e2