[INFO] cloning repository https://github.com/Magnap/game-trees-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Magnap/game-trees-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMagnap%2Fgame-trees-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMagnap%2Fgame-trees-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 141a0f2d86fef40cf82dafed7b86f340ec5bec95
[INFO] testing Magnap/game-trees-rs against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMagnap%2Fgame-trees-rs" "/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/Magnap/game-trees-rs 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/Magnap/game-trees-rs
[INFO] finished tweaking git repo https://github.com/Magnap/game-trees-rs
[INFO] tweaked toml for git repo https://github.com/Magnap/game-trees-rs written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/Magnap/game-trees-rs 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] [stderr]     Blocking waiting for file lock on package cache
[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" "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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f39f6ac8b383b624b110e6636580591c95a1d5af71f5a19f831e2990613505e2
[INFO] running `Command { std: "docker" "start" "-a" "f39f6ac8b383b624b110e6636580591c95a1d5af71f5a19f831e2990613505e2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f39f6ac8b383b624b110e6636580591c95a1d5af71f5a19f831e2990613505e2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f39f6ac8b383b624b110e6636580591c95a1d5af71f5a19f831e2990613505e2", kill_on_drop: false }`
[INFO] [stdout] f39f6ac8b383b624b110e6636580591c95a1d5af71f5a19f831e2990613505e2
[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" "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] [stdout] 47311544f282594e6bc671b29e1e0bea5c283b99671f8d1304e3da698b10befc
[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" "47311544f282594e6bc671b29e1e0bea5c283b99671f8d1304e3da698b10befc", kill_on_drop: false }`
[INFO] [stderr]    Compiling either v1.1.0
[INFO] [stderr]    Compiling fnv v1.0.5
[INFO] [stderr]    Compiling itertools v0.6.1
[INFO] [stderr]    Compiling game-trees v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(type_ascription)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `game-trees`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "47311544f282594e6bc671b29e1e0bea5c283b99671f8d1304e3da698b10befc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47311544f282594e6bc671b29e1e0bea5c283b99671f8d1304e3da698b10befc", kill_on_drop: false }`
[INFO] [stdout] 47311544f282594e6bc671b29e1e0bea5c283b99671f8d1304e3da698b10befc