[INFO] cloning repository https://github.com/jail-maker/check_ip
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jail-maker/check_ip" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjail-maker%2Fcheck_ip", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjail-maker%2Fcheck_ip'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 93449c8958bd8e4bf5330d9b9a8c8e2ee24d17f1
[INFO] testing jail-maker/check_ip against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjail-maker%2Fcheck_ip" "/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/jail-maker/check_ip 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/jail-maker/check_ip
[INFO] finished tweaking git repo https://github.com/jail-maker/check_ip
[INFO] tweaked toml for git repo https://github.com/jail-maker/check_ip written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/jail-maker/check_ip 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]  Downloading crates ...
[INFO] [stderr]   Downloaded ipnetwork v0.12.6
[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] d746c445aa1b6a7eb85d6c1e3b4c681daca62d2fdf3c8c2b0e0f3068fb468daf
[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" "d746c445aa1b6a7eb85d6c1e3b4c681daca62d2fdf3c8c2b0e0f3068fb468daf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d746c445aa1b6a7eb85d6c1e3b4c681daca62d2fdf3c8c2b0e0f3068fb468daf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d746c445aa1b6a7eb85d6c1e3b4c681daca62d2fdf3c8c2b0e0f3068fb468daf", kill_on_drop: false }`
[INFO] [stdout] d746c445aa1b6a7eb85d6c1e3b4c681daca62d2fdf3c8c2b0e0f3068fb468daf
[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] [stdout] 143e966516ab818fccb1e830576665c7fdc89927ea6bdff3ebd44d9d0436157f
[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" "143e966516ab818fccb1e830576665c7fdc89927ea6bdff3ebd44d9d0436157f", kill_on_drop: false }`
[INFO] [stderr]    Compiling yaml-rust v0.3.5
[INFO] [stderr]    Compiling unicode-segmentation v1.1.0
[INFO] [stderr]    Compiling vec_map v0.8.0
[INFO] [stderr]    Compiling ansi_term v0.9.0
[INFO] [stderr]    Compiling ipnetwork v0.12.6
[INFO] [stderr]    Compiling term_size v0.3.0
[INFO] [stderr]    Compiling atty v0.2.2
[INFO] [stderr]    Compiling serde_json v1.0.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/ipnetwork-0.12.6/src/lib.rs:6:40
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![cfg_attr(feature = "ipv6-iterator", feature(i128_type))]
[INFO] [stdout]   |                                        ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/ipnetwork-0.12.6/src/lib.rs:7:39
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![cfg_attr(feature = "ipv6-methods", feature(i128_type))]
[INFO] [stdout]   |                                       ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling textwrap v0.6.0
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ipnetwork`
[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 `Command { std: "docker" "inspect" "143e966516ab818fccb1e830576665c7fdc89927ea6bdff3ebd44d9d0436157f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "143e966516ab818fccb1e830576665c7fdc89927ea6bdff3ebd44d9d0436157f", kill_on_drop: false }`
[INFO] [stdout] 143e966516ab818fccb1e830576665c7fdc89927ea6bdff3ebd44d9d0436157f