[INFO] fetching crate quantum_random 0.1.0...
[INFO] testing quantum_random-0.1.0 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate quantum_random 0.1.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate quantum_random 0.1.0 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 quantum_random 0.1.0
[INFO] finished tweaking crates.io crate quantum_random 0.1.0
[INFO] tweaked toml for crates.io crate quantum_random 0.1.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded redox_users v0.2.0
[INFO] [stderr]   Downloaded dirs-2 v1.1.0
[INFO] [stderr]   Downloaded libmath v0.2.1
[INFO] [stderr]   Downloaded mut_static v5.0.0
[INFO] [stderr]   Downloaded futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-select-macro-preview v0.3.0-alpha.18
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] a6c1deb3a0d59efa3f804228ce1af488128badb24ebf942fb17e7e9703d3d89a
[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" "a6c1deb3a0d59efa3f804228ce1af488128badb24ebf942fb17e7e9703d3d89a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a6c1deb3a0d59efa3f804228ce1af488128badb24ebf942fb17e7e9703d3d89a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a6c1deb3a0d59efa3f804228ce1af488128badb24ebf942fb17e7e9703d3d89a", kill_on_drop: false }`
[INFO] [stdout] a6c1deb3a0d59efa3f804228ce1af488128badb24ebf942fb17e7e9703d3d89a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 1ed2bb90ff634b7c780b8ff4fe8ac63edb118337f3bd95d7cf5818e12365f479
[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" "1ed2bb90ff634b7c780b8ff4fe8ac63edb118337f3bd95d7cf5818e12365f479", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling openssl v0.10.32
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling regex-syntax v0.6.21
[INFO] [stderr]    Compiling native-tls v0.2.7
[INFO] [stderr]    Compiling encoding_rs v0.8.26
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling openssl-probe v0.1.2
[INFO] [stderr]    Compiling dtoa v0.4.7
[INFO] [stderr]    Compiling error-chain v0.10.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.1
[INFO] [stderr]    Compiling memoffset v0.6.1
[INFO] [stderr]    Compiling try_from v0.3.2
[INFO] [stderr]    Compiling openssl-sys v0.9.60
[INFO] [stderr]    Compiling error-chain v0.12.4
[INFO] [stderr]    Compiling form_urlencoded v1.0.0
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling mut_static v5.0.0
[INFO] [stderr]    Compiling dirs-2 v1.1.0
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling idna v0.1.5
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling flate2 v1.0.19
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling atoi v0.3.3
[INFO] [stderr]    Compiling mime_guess v2.0.3
[INFO] [stderr]    Compiling libmath v0.2.1
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling uuid v0.7.4
[INFO] [stderr]    Compiling regex v1.4.2
[INFO] [stderr]    Compiling url v1.7.2
[INFO] [stderr]    Compiling url v2.2.0
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.1
[INFO] [stderr]    Compiling crossbeam-channel v0.5.0
[INFO] [stderr]    Compiling publicsuffix v1.5.4
[INFO] [stderr]    Compiling cookie v0.12.0
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling rayon-core v1.9.0
[INFO] [stderr]    Compiling failure v0.1.8
[INFO] [stderr]    Compiling rayon v1.5.0
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.18
[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/futures-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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 `futures-util-preview`
[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" "1ed2bb90ff634b7c780b8ff4fe8ac63edb118337f3bd95d7cf5818e12365f479", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1ed2bb90ff634b7c780b8ff4fe8ac63edb118337f3bd95d7cf5818e12365f479", kill_on_drop: false }`
[INFO] [stdout] 1ed2bb90ff634b7c780b8ff4fe8ac63edb118337f3bd95d7cf5818e12365f479