[INFO] fetching crate jn 0.1.0...
[INFO] testing jn-0.1.0 against 1.60.0 for beta-1.61-1
[INFO] extracting crate jn 0.1.0 into /workspace/builds/worker-17/source
[INFO] validating manifest of crates.io crate jn 0.1.0 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-17/source/rust-toolchain
[INFO] started tweaking crates.io crate jn 0.1.0
[INFO] finished tweaking crates.io crate jn 0.1.0
[INFO] tweaked toml for crates.io crate jn 0.1.0 written to /workspace/builds/worker-17/source/Cargo.toml
[INFO] crate crates.io crate jn 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded hostname v0.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5e3cf54e9334ad199f7b588c0ba7bf2ceb65845ace59bb7175cd159966d69a24
[INFO] running `Command { std: "docker" "start" "-a" "5e3cf54e9334ad199f7b588c0ba7bf2ceb65845ace59bb7175cd159966d69a24", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5e3cf54e9334ad199f7b588c0ba7bf2ceb65845ace59bb7175cd159966d69a24", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e3cf54e9334ad199f7b588c0ba7bf2ceb65845ace59bb7175cd159966d69a24", kill_on_drop: false }`
[INFO] [stdout] 5e3cf54e9334ad199f7b588c0ba7bf2ceb65845ace59bb7175cd159966d69a24
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e2959f6234eddeb5e6a2d7562bd854dd3e60b019329350cd766e5f28693dc11a
[INFO] running `Command { std: "docker" "start" "-a" "e2959f6234eddeb5e6a2d7562bd854dd3e60b019329350cd766e5f28693dc11a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.8
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling ryu v1.0.2
[INFO] [stderr]    Compiling vec_map v0.8.1
[INFO] [stderr]    Compiling itoa v0.4.5
[INFO] [stderr]    Compiling match_cfg v0.1.0
[INFO] [stderr]    Compiling dirs-sys v0.3.4
[INFO] [stderr]    Compiling time v0.1.42
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling hostname v0.3.0
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling dirs v2.0.2
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]    Compiling chrono v0.4.10
[INFO] [stderr]    Compiling serde_json v1.0.48
[INFO] [stderr]    Compiling jn 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:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(map_first_last)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `jn` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "e2959f6234eddeb5e6a2d7562bd854dd3e60b019329350cd766e5f28693dc11a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2959f6234eddeb5e6a2d7562bd854dd3e60b019329350cd766e5f28693dc11a", kill_on_drop: false }`
[INFO] [stdout] e2959f6234eddeb5e6a2d7562bd854dd3e60b019329350cd766e5f28693dc11a