[INFO] cloning repository https://github.com/tsatke/lprefix
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tsatke/lprefix" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftsatke%2Flprefix", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftsatke%2Flprefix'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b29a91e9d0f7ab1efcbdb574df487a1995ceb584
[INFO] testing tsatke/lprefix against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftsatke%2Flprefix" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tsatke/lprefix 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/tsatke/lprefix
[INFO] finished tweaking git repo https://github.com/tsatke/lprefix
[INFO] tweaked toml for git repo https://github.com/tsatke/lprefix written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/tsatke/lprefix 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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 3d6e573c00d09b6af748f472e8fbd13fc4661865acce42d2bdb057f41840fdf1
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "3d6e573c00d09b6af748f472e8fbd13fc4661865acce42d2bdb057f41840fdf1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3d6e573c00d09b6af748f472e8fbd13fc4661865acce42d2bdb057f41840fdf1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3d6e573c00d09b6af748f472e8fbd13fc4661865acce42d2bdb057f41840fdf1", kill_on_drop: false }`
[INFO] [stdout] 3d6e573c00d09b6af748f472e8fbd13fc4661865acce42d2bdb057f41840fdf1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] e722f95d116c9e5a05de203b52dc6b6d046fbdf5e4f547b99a7c9df49782bb0a
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "e722f95d116c9e5a05de203b52dc6b6d046fbdf5e4f547b99a7c9df49782bb0a", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling numtoa v0.1.0
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling termion v1.5.6
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling lprefix v0.1.1 (/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(stdin_forwarders)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(box_syntax)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lprefix` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "e722f95d116c9e5a05de203b52dc6b6d046fbdf5e4f547b99a7c9df49782bb0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e722f95d116c9e5a05de203b52dc6b6d046fbdf5e4f547b99a7c9df49782bb0a", kill_on_drop: false }`
[INFO] [stdout] e722f95d116c9e5a05de203b52dc6b6d046fbdf5e4f547b99a7c9df49782bb0a