[INFO] crate mcio 0.3.1 is already in cache
[INFO] testing mcio-0.3.1 against 1.44.0 for beta-1.45-1
[INFO] extracting crate mcio 0.3.1 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate mcio 0.3.1 on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate mcio 0.3.1
[INFO] finished tweaking crates.io crate mcio 0.3.1
[INFO] tweaked toml for crates.io crate mcio 0.3.1 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate crates.io crate mcio 0.3.1 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] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 724feeede31bd450e929a95965da7e0336cf535bf4eed017b660a369bfc2b4cf
[INFO] running `"docker" "start" "-a" "724feeede31bd450e929a95965da7e0336cf535bf4eed017b660a369bfc2b4cf"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling linked-hash-map v0.5.2
[INFO] [stderr]    Compiling backtrace-sys v0.1.35
[INFO] [stderr]    Compiling tokio-sync v0.1.8
[INFO] [stderr]    Compiling crossbeam-queue v0.2.1
[INFO] [stderr]    Compiling socket2 v0.3.12
[INFO] [stderr]    Compiling hostname v0.3.1
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling mio v0.6.21
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling resolv-conf v0.6.3
[INFO] [stderr]    Compiling tokio-threadpool v0.1.18
[INFO] [stderr]    Compiling lru-cache v0.1.2
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling tokio-io v0.1.13
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling backtrace v0.2.3
[INFO] [stderr]    Compiling tokio-reactor v0.1.12
[INFO] [stderr]    Compiling tokio-codec v0.1.2
[INFO] [stderr]    Compiling tokio-fs v0.1.7
[INFO] [stderr]    Compiling error-chain v0.1.12
[INFO] [stderr]    Compiling tokio-udp v0.1.6
[INFO] [stderr]    Compiling tokio-tcp v0.1.4
[INFO] [stderr]    Compiling tokio-uds v0.2.6
[INFO] [stderr]    Compiling trust-dns-proto v0.4.3
[INFO] [stderr]    Compiling tokio v0.1.22
[INFO] [stderr]    Compiling trust-dns-resolver v0.9.1
[INFO] [stderr]    Compiling serde_json v1.0.51
[INFO] [stderr]    Compiling mcio v0.3.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(external_doc)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Name`
[INFO] [stderr]   --> src/lib.rs:14:36
[INFO] [stderr]    |
[INFO] [stderr] 14 | use trust_dns_resolver::{Resolver, Name};
[INFO] [stderr]    |                                    ^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error; 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `mcio`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "724feeede31bd450e929a95965da7e0336cf535bf4eed017b660a369bfc2b4cf"`
[INFO] running `"docker" "rm" "-f" "724feeede31bd450e929a95965da7e0336cf535bf4eed017b660a369bfc2b4cf"`
[INFO] [stdout] 724feeede31bd450e929a95965da7e0336cf535bf4eed017b660a369bfc2b4cf