[INFO] fetching crate tari_comms 0.2.7...
[INFO] testing tari_comms-0.2.7 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate tari_comms 0.2.7 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate tari_comms 0.2.7 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 tari_comms 0.2.7
[INFO] finished tweaking crates.io crate tari_comms 0.2.7
[INFO] tweaked toml for crates.io crate tari_comms 0.2.7 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate crates.io crate tari_comms 0.2.7 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 serde_json v1.0.58
[INFO] [stderr]   Downloaded flate2 v1.0.18
[INFO] [stderr]   Downloaded structopt-derive v0.4.12
[INFO] [stderr]   Downloaded tower-make v0.3.0
[INFO] [stderr]   Downloaded tari_crypto v0.8.0
[INFO] [stderr]   Downloaded regex-syntax v0.6.19
[INFO] [stderr]   Downloaded regex v1.4.0
[INFO] [stderr]   Downloaded structopt v0.3.19
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] 92ae68af8b7306629ff108fc987449f5ebe4dcda724370330156110efbff29eb
[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" "92ae68af8b7306629ff108fc987449f5ebe4dcda724370330156110efbff29eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "92ae68af8b7306629ff108fc987449f5ebe4dcda724370330156110efbff29eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "92ae68af8b7306629ff108fc987449f5ebe4dcda724370330156110efbff29eb", kill_on_drop: false }`
[INFO] [stdout] 92ae68af8b7306629ff108fc987449f5ebe4dcda724370330156110efbff29eb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] bb5859ebf91b179be0f5e9c4bb3cd55095070400d6c63caba4d3dbad92d7bb35
[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" "bb5859ebf91b179be0f5e9c4bb3cd55095070400d6c63caba4d3dbad92d7bb35", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling serde v1.0.116
[INFO] [stderr]    Compiling futures-core v0.3.6
[INFO] [stderr]    Compiling ppv-lite86 v0.2.9
[INFO] [stderr]    Compiling cc v1.0.61
[INFO] [stderr]    Compiling futures-sink v0.3.6
[INFO] [stderr]    Compiling pin-project-lite v0.1.10
[INFO] [stderr]    Compiling once_cell v1.4.1
[INFO] [stderr]    Compiling futures-io v0.3.6
[INFO] [stderr]    Compiling unicode-segmentation v1.6.0
[INFO] [stderr]    Compiling subtle v2.3.0
[INFO] [stderr]    Compiling tinyvec v0.3.4
[INFO] [stderr]    Compiling data-encoding v2.3.0
[INFO] [stderr]    Compiling smallvec v1.4.2
[INFO] [stderr]    Compiling block-padding v0.2.1
[INFO] [stderr]    Compiling opaque-debug v0.3.0
[INFO] [stderr]    Compiling arrayvec v0.5.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/subtle-2.3.0/src/lib.rs:12:34
[INFO] [stdout]    |
[INFO] [stdout] 12 | #![cfg_attr(feature = "nightly", feature(external_doc))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling bitstring v0.1.1
[INFO] [stderr]    Compiling nohash-hasher v0.2.0
[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 `subtle`
[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" "bb5859ebf91b179be0f5e9c4bb3cd55095070400d6c63caba4d3dbad92d7bb35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb5859ebf91b179be0f5e9c4bb3cd55095070400d6c63caba4d3dbad92d7bb35", kill_on_drop: false }`
[INFO] [stdout] bb5859ebf91b179be0f5e9c4bb3cd55095070400d6c63caba4d3dbad92d7bb35