[INFO] cloning repository https://github.com/psFried/roman-numerals-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/psFried/roman-numerals-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FpsFried%2Froman-numerals-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FpsFried%2Froman-numerals-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a5eb19ba0468ee970bf2118998631a74df84ab43
[INFO] testing psFried/roman-numerals-rust against beta-2021-09-08 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FpsFried%2Froman-numerals-rust" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/psFried/roman-numerals-rust on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/psFried/roman-numerals-rust
[INFO] finished tweaking git repo https://github.com/psFried/roman-numerals-rust
[INFO] tweaked toml for git repo https://github.com/psFried/roman-numerals-rust written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/psFried/roman-numerals-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dc1cabd77ef82b86ae9f4afee94b88f86c63a12becbeb12328e695b3a3073929
[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" "dc1cabd77ef82b86ae9f4afee94b88f86c63a12becbeb12328e695b3a3073929", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dc1cabd77ef82b86ae9f4afee94b88f86c63a12becbeb12328e695b3a3073929", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dc1cabd77ef82b86ae9f4afee94b88f86c63a12becbeb12328e695b3a3073929", kill_on_drop: false }`
[INFO] [stdout] dc1cabd77ef82b86ae9f4afee94b88f86c63a12becbeb12328e695b3a3073929
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ea7c7ba0f563d7490c9fae6c2836833319045ce5f76abe4ec6ddc46ab9db431c
[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" "ea7c7ba0f563d7490c9fae6c2836833319045ce5f76abe4ec6ddc46ab9db431c", kill_on_drop: false }`
[INFO] [stderr]    Compiling roman v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `std::slice::SliceConcatExt`
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::slice::SliceConcatExt;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ no `SliceConcatExt` in `slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0425]: cannot find function `set_exit_status` in module `std::env`
[INFO] [stdout]   --> src/main.rs:27:15
[INFO] [stdout]    |
[INFO] [stdout] 27 |     std::env::set_exit_status(1);
[INFO] [stdout]    |               ^^^^^^^^^^^^^^^ not found in `std::env`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(collections)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(exit_status)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0425, E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0425`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `roman` due to 5 previous errors
[INFO] running `Command { std: "docker" "inspect" "ea7c7ba0f563d7490c9fae6c2836833319045ce5f76abe4ec6ddc46ab9db431c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea7c7ba0f563d7490c9fae6c2836833319045ce5f76abe4ec6ddc46ab9db431c", kill_on_drop: false }`
[INFO] [stdout] ea7c7ba0f563d7490c9fae6c2836833319045ce5f76abe4ec6ddc46ab9db431c