[INFO] fetching crate overlord 0.2.1...
[INFO] testing overlord-0.2.1 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate overlord 0.2.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate overlord 0.2.1 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate overlord 0.2.1
[INFO] finished tweaking crates.io crate overlord 0.2.1
[INFO] tweaked toml for crates.io crate overlord 0.2.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate overlord 0.2.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded trackable_derive v0.1.3
[INFO] [stderr]   Downloaded dyn-clone v1.0.2
[INFO] [stderr]   Downloaded trackable v0.2.23
[INFO] [stderr]   Downloaded async-trait v0.1.36
[INFO] [stderr]   Downloaded hasher v0.1.3
[INFO] [stderr]   Downloaded adler32 v1.1.0
[INFO] [stderr]   Downloaded rustracing v0.4.0
[INFO] [stderr]   Downloaded prime_tools v0.2.2
[INFO] [stderr]   Downloaded creep v0.2.2
[INFO] [stderr]   Downloaded rustracing_jaeger v0.4.1
[INFO] [stderr]   Downloaded muta-apm v0.1.0-alpha.15
[INFO] [stderr]   Downloaded derive_more v0.99.8
[INFO] [stderr]   Downloaded thrift_codec v0.1.1
[INFO] [stderr]   Downloaded libmath v0.1.4
[INFO] [stderr]   Downloaded backtrace v0.3.49
[INFO] [stderr]   Downloaded rlp v0.4.5
[INFO] [stderr]   Downloaded muta-apm-derive v0.1.0-alpha.12
[INFO] [stderr]   Downloaded serde_json v1.0.55
[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" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 550b417f7ad05eaf9be972a912cafd617a32d2d00d698057f4987b2ce4a04f8e
[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" "550b417f7ad05eaf9be972a912cafd617a32d2d00d698057f4987b2ce4a04f8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "550b417f7ad05eaf9be972a912cafd617a32d2d00d698057f4987b2ce4a04f8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "550b417f7ad05eaf9be972a912cafd617a32d2d00d698057f4987b2ce4a04f8e", kill_on_drop: false }`
[INFO] [stdout] 550b417f7ad05eaf9be972a912cafd617a32d2d00d698057f4987b2ce4a04f8e
[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" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b40d1ed22a093f71243af075a78bf79123da32026e4babbdf11db178b35bf5e7
[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" "b40d1ed22a093f71243af075a78bf79123da32026e4babbdf11db178b35bf5e7", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.31
[INFO] [stderr]    Compiling serde v1.0.112
[INFO] [stderr]    Compiling serde_json v1.0.55
[INFO] [stderr]    Compiling dyn-clone v1.0.2
[INFO] [stderr]    Compiling bit-vec v0.6.2
[INFO] [stderr]    Compiling rustc-hex v2.1.0
[INFO] [stderr]    Compiling addr2line v0.12.1
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling parking_lot_core v0.7.2
[INFO] [stderr]    Compiling hostname v0.3.1
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling rand_pcg v0.2.1
[INFO] [stderr]    Compiling creep v0.2.2
[INFO] [stderr]    Compiling rlp v0.4.5
[INFO] [stderr]    Compiling backtrace v0.3.49
[INFO] [stderr]    Compiling parking_lot v0.10.2
[INFO] [stderr]    Compiling rand v0.3.23
[INFO] [stderr]    Compiling libmath v0.1.4
[INFO] [stderr]    Compiling prime_tools v0.2.2
[INFO] [stderr]    Compiling serde_derive v1.0.112
[INFO] [stderr]    Compiling trackable_derive v0.1.3
[INFO] [stderr]    Compiling pin-project-internal v0.4.22
[INFO] [stderr]    Compiling futures-macro v0.3.5
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling async-trait v0.1.36
[INFO] [stderr]    Compiling derive_more v0.99.8
[INFO] [stderr]    Compiling trackable v0.2.23
[INFO] [stderr]    Compiling thrift_codec v0.1.1
[INFO] [stderr]    Compiling rustracing v0.4.0
[INFO] [stderr]    Compiling rustracing_jaeger v0.4.1
[INFO] [stderr]    Compiling pin-project v0.4.22
[INFO] [stderr]    Compiling futures-util v0.3.5
[INFO] [stderr]    Compiling futures-executor v0.3.5
[INFO] [stderr]    Compiling futures v0.3.5
[INFO] [stderr]    Compiling bytes v0.5.5
[INFO] [stderr]    Compiling tokio v0.2.21
[INFO] [stderr]    Compiling muta-apm-derive v0.1.0-alpha.12
[INFO] [stderr]    Compiling muta-apm v0.1.0-alpha.15
[INFO] [stderr]    Compiling overlord v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `overlord`
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "b40d1ed22a093f71243af075a78bf79123da32026e4babbdf11db178b35bf5e7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b40d1ed22a093f71243af075a78bf79123da32026e4babbdf11db178b35bf5e7", kill_on_drop: false }`
[INFO] [stdout] b40d1ed22a093f71243af075a78bf79123da32026e4babbdf11db178b35bf5e7