[INFO] cloning repository https://github.com/msiemens/rust-tictactoe
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/msiemens/rust-tictactoe" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmsiemens%2Frust-tictactoe", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmsiemens%2Frust-tictactoe'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a8886bdf40bef1bf5b6c9ea806e9155d6206bcdf
[INFO] testing msiemens/rust-tictactoe against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmsiemens%2Frust-tictactoe" "/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/msiemens/rust-tictactoe on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/msiemens/rust-tictactoe
[INFO] finished tweaking git repo https://github.com/msiemens/rust-tictactoe
[INFO] tweaked toml for git repo https://github.com/msiemens/rust-tictactoe written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/msiemens/rust-tictactoe already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 684aab75ba720d3a7c8b48df425ee4b67c0564911a09ddfd2a123116a74cf50f
[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" "684aab75ba720d3a7c8b48df425ee4b67c0564911a09ddfd2a123116a74cf50f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "684aab75ba720d3a7c8b48df425ee4b67c0564911a09ddfd2a123116a74cf50f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "684aab75ba720d3a7c8b48df425ee4b67c0564911a09ddfd2a123116a74cf50f", kill_on_drop: false }`
[INFO] [stdout] 684aab75ba720d3a7c8b48df425ee4b67c0564911a09ddfd2a123116a74cf50f
[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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", 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] 6af0cd2cfe99f5bd10af66e45a76b61abdf94fecd3ac56a89795f28fa2dcf759
[INFO] running `Command { std: "docker" "start" "-a" "6af0cd2cfe99f5bd10af66e45a76b61abdf94fecd3ac56a89795f28fa2dcf759", kill_on_drop: false }`
[INFO] [stderr]    Compiling enum-display-derive v0.1.0
[INFO] [stderr]    Compiling mcts 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(vec_remove_item)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::vec::Vec::<T>::remove_item`: Removing the first item equal to a needle is already easily possible with iterators and the current Vec methods. Furthermore, having a method for one particular case of removal (linear search, only the first item, no swap remove) but not for others is inconsistent. This method will be removed soon.
[INFO] [stdout]   --> src/mcts.rs:55:21
[INFO] [stdout]    |
[INFO] [stdout] 55 |             actions.remove_item(&child.action.expect("Child has no action"));
[INFO] [stdout]    |                     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[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 `mcts`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "6af0cd2cfe99f5bd10af66e45a76b61abdf94fecd3ac56a89795f28fa2dcf759", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6af0cd2cfe99f5bd10af66e45a76b61abdf94fecd3ac56a89795f28fa2dcf759", kill_on_drop: false }`
[INFO] [stdout] 6af0cd2cfe99f5bd10af66e45a76b61abdf94fecd3ac56a89795f28fa2dcf759