[INFO] cloning repository https://github.com/alevy/iterator_bench
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/alevy/iterator_bench" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falevy%2Fiterator_bench", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falevy%2Fiterator_bench'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 026d67b174f1304e34626850dcc9c3aecc155f2b
[INFO] testing alevy/iterator_bench 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%2Falevy%2Fiterator_bench" "/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/alevy/iterator_bench 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] removed /workspace/builds/worker-0/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/alevy/iterator_bench
[INFO] finished tweaking git repo https://github.com/alevy/iterator_bench
[INFO] tweaked toml for git repo https://github.com/alevy/iterator_bench written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/alevy/iterator_bench 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] 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" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a57d6c8712766c5cb5744b7194ff711673694b1d249d2b4c59fea799c82a9290
[INFO] running `Command { std: "docker" "start" "-a" "a57d6c8712766c5cb5744b7194ff711673694b1d249d2b4c59fea799c82a9290", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a57d6c8712766c5cb5744b7194ff711673694b1d249d2b4c59fea799c82a9290", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a57d6c8712766c5cb5744b7194ff711673694b1d249d2b4c59fea799c82a9290", kill_on_drop: false }`
[INFO] [stdout] a57d6c8712766c5cb5744b7194ff711673694b1d249d2b4c59fea799c82a9290
[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" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 664fc2ed7527308eb3547d105a35a69e049e35c8a91abc784cf7971bfcf87fb2
[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" "664fc2ed7527308eb3547d105a35a69e049e35c8a91abc784cf7971bfcf87fb2", kill_on_drop: false }`
[INFO] [stderr]    Compiling iterator_bench v0.1.0 (/opt/rustwide/workdir)
[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(stmt_expr_attributes, test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused doc comment
[INFO] [stdout]   --> src/main.rs:63:1
[INFO] [stdout]    |
[INFO] [stdout] 63 | / /// This is the implementation we would write in C.
[INFO] [stdout] 64 | | ///
[INFO] [stdout] 65 | | ///   * It iterators over the input array with a C-style for-loop.
[INFO] [stdout] 66 | | ///
[INFO] [stdout] ...  |
[INFO] [stdout] 77 | | /// The compiler has managed to compile this into packed moves. So there are only 20,000 iterations
[INFO] [stdout] 78 | | /// of the loop with 5 instructions each.
[INFO] [stdout]    | |_----------------------------------------^
[INFO] [stdout]    |   |
[INFO] [stdout]    |   rustdoc does not generate documentation for macro invocations
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stdout]    = help: to document an item produced by a macro, the macro must produce the documentation as part of its expansion
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `iterator_bench` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "664fc2ed7527308eb3547d105a35a69e049e35c8a91abc784cf7971bfcf87fb2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "664fc2ed7527308eb3547d105a35a69e049e35c8a91abc784cf7971bfcf87fb2", kill_on_drop: false }`
[INFO] [stdout] 664fc2ed7527308eb3547d105a35a69e049e35c8a91abc784cf7971bfcf87fb2