[INFO] cloning repository https://github.com/Magnap/game-trees-rs
[INFO] running `"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"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMagnap%2Fgame-trees-rs'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 141a0f2d86fef40cf82dafed7b86f340ec5bec95
[INFO] testing Magnap/game-trees-rs against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMagnap%2Fgame-trees-rs" "/workspace/builds/worker-0/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Magnap/game-trees-rs on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-0/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 `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4148ea95303b379d3238558e9c5a2f6b16e708c40f3fb3d4f77567a435805a4b
[INFO] running `"docker" "start" "-a" "4148ea95303b379d3238558e9c5a2f6b16e708c40f3fb3d4f77567a435805a4b"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling libc v0.2.29
[INFO] [stderr]    Compiling either v1.1.0
[INFO] [stderr]    Compiling fnv v1.0.5
[INFO] [stderr]    Compiling itertools v0.6.1
[INFO] [stderr]    Compiling rand v0.3.16
[INFO] [stderr]    Compiling game-trees v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(type_ascription)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `game-trees`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "4148ea95303b379d3238558e9c5a2f6b16e708c40f3fb3d4f77567a435805a4b"`
[INFO] running `"docker" "rm" "-f" "4148ea95303b379d3238558e9c5a2f6b16e708c40f3fb3d4f77567a435805a4b"`
[INFO] [stdout] 4148ea95303b379d3238558e9c5a2f6b16e708c40f3fb3d4f77567a435805a4b