[INFO] cloning repository https://github.com/MrMcEpic/Rust-Monty-Hall
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/MrMcEpic/Rust-Monty-Hall" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMrMcEpic%2FRust-Monty-Hall", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMrMcEpic%2FRust-Monty-Hall'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 102cbd7793ddf4dfbe7f8c644dea1b5070fdb86a
[INFO] testing MrMcEpic/Rust-Monty-Hall against 1.54.0 for beta-1.55-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMrMcEpic%2FRust-Monty-Hall" "/workspace/builds/worker-86/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-86/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MrMcEpic/Rust-Monty-Hall on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/MrMcEpic/Rust-Monty-Hall
[INFO] finished tweaking git repo https://github.com/MrMcEpic/Rust-Monty-Hall
[INFO] tweaked toml for git repo https://github.com/MrMcEpic/Rust-Monty-Hall written to /workspace/builds/worker-86/source/Cargo.toml
[INFO] crate git repo https://github.com/MrMcEpic/Rust-Monty-Hall already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cc9821b3a4a46c5bafc663f768f88c44c7f60cf1e91e32d437535faa195145fd
[INFO] running `Command { std: "docker" "start" "-a" "cc9821b3a4a46c5bafc663f768f88c44c7f60cf1e91e32d437535faa195145fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cc9821b3a4a46c5bafc663f768f88c44c7f60cf1e91e32d437535faa195145fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cc9821b3a4a46c5bafc663f768f88c44c7f60cf1e91e32d437535faa195145fd", kill_on_drop: false }`
[INFO] [stdout] cc9821b3a4a46c5bafc663f768f88c44c7f60cf1e91e32d437535faa195145fd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a57ec51635ff20ebb714fed1f5ad3388db47a9d841cc6d9dea1e433a4fec37b4
[INFO] running `Command { std: "docker" "start" "-a" "a57ec51635ff20ebb714fed1f5ad3388db47a9d841cc6d9dea1e433a4fec37b4", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling c2-chacha v0.2.3
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling boxes v0.1.0 (/opt/rustwide/workdir/boxes)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> boxes/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(vec_remove_item, drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `remove_item` found for struct `Vec<usize>` in the current scope
[INFO] [stdout]   --> boxes/src/lib.rs:41:12
[INFO] [stdout]    |
[INFO] [stdout] 41 |             options.remove_item(&first_pick.0); //removes their inital box pick from a list of possible boxes
[INFO] [stdout]    |                     ^^^^^^^^^^^ method not found in `Vec<usize>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `boxes`
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0599.
[INFO] [stdout] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a57ec51635ff20ebb714fed1f5ad3388db47a9d841cc6d9dea1e433a4fec37b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a57ec51635ff20ebb714fed1f5ad3388db47a9d841cc6d9dea1e433a4fec37b4", kill_on_drop: false }`
[INFO] [stdout] a57ec51635ff20ebb714fed1f5ad3388db47a9d841cc6d9dea1e433a4fec37b4
