[INFO] cloning repository https://github.com/superobertking/SlidingMatrixSolver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/superobertking/SlidingMatrixSolver" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsuperobertking%2FSlidingMatrixSolver", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsuperobertking%2FSlidingMatrixSolver'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 769369e8c27c696e2196f94aa2c8f1e9b6fb06b7
[INFO] testing superobertking/SlidingMatrixSolver against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsuperobertking%2FSlidingMatrixSolver" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/superobertking/SlidingMatrixSolver 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/superobertking/SlidingMatrixSolver
[INFO] finished tweaking git repo https://github.com/superobertking/SlidingMatrixSolver
[INFO] tweaked toml for git repo https://github.com/superobertking/SlidingMatrixSolver written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/superobertking/SlidingMatrixSolver 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 1776c9c5891241396d8c33de9f48ae201621d27675681a75570ba489b233f1b5
[INFO] running `Command { std: "docker" "start" "-a" "1776c9c5891241396d8c33de9f48ae201621d27675681a75570ba489b233f1b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1776c9c5891241396d8c33de9f48ae201621d27675681a75570ba489b233f1b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1776c9c5891241396d8c33de9f48ae201621d27675681a75570ba489b233f1b5", kill_on_drop: false }`
[INFO] [stdout] 1776c9c5891241396d8c33de9f48ae201621d27675681a75570ba489b233f1b5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 8ec7adea81428f1da59d6830b3272ede592f1b3b136d736b3f2c64509220e137
[INFO] running `Command { std: "docker" "start" "-a" "8ec7adea81428f1da59d6830b3272ede592f1b3b136d736b3f2c64509220e137", kill_on_drop: false }`
[INFO] [stderr]    Compiling solver 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(is_sorted)]
[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(const_generics)]
[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 `solver` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "8ec7adea81428f1da59d6830b3272ede592f1b3b136d736b3f2c64509220e137", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ec7adea81428f1da59d6830b3272ede592f1b3b136d736b3f2c64509220e137", kill_on_drop: false }`
[INFO] [stdout] 8ec7adea81428f1da59d6830b3272ede592f1b3b136d736b3f2c64509220e137