[INFO] fetching crate quantum_random 0.1.0...
[INFO] documenting quantum_random-0.1.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate quantum_random 0.1.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate quantum_random 0.1.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "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-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cdc6353838f1d4aa2bf24e4c2c6ee67d937b043eb7200cb1176e62a118b8229b
[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" "cdc6353838f1d4aa2bf24e4c2c6ee67d937b043eb7200cb1176e62a118b8229b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cdc6353838f1d4aa2bf24e4c2c6ee67d937b043eb7200cb1176e62a118b8229b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cdc6353838f1d4aa2bf24e4c2c6ee67d937b043eb7200cb1176e62a118b8229b", kill_on_drop: false }`
[INFO] [stdout] cdc6353838f1d4aa2bf24e4c2c6ee67d937b043eb7200cb1176e62a118b8229b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "RUSTDOCFLAGS=--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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 47402eb392da67f5adb2cf53e8bbcd53422c9f500aa46d029d913722a7b62b8f
[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" "47402eb392da67f5adb2cf53e8bbcd53422c9f500aa46d029d913722a7b62b8f", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking error-chain v0.10.0
[INFO] [stderr]     Checking dirs-2 v1.1.0
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]     Checking atoi v0.3.2
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]     Checking libmath v0.2.1
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]     Checking chrono v0.4.19
[INFO] [stderr]     Checking mut_static v5.0.0
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[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/lock_api-0.3.4/src/lib.rs:91:34
[INFO] [stdout]    |
[INFO] [stdout] 91 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[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 `lock_api`.
[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" "47402eb392da67f5adb2cf53e8bbcd53422c9f500aa46d029d913722a7b62b8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47402eb392da67f5adb2cf53e8bbcd53422c9f500aa46d029d913722a7b62b8f", kill_on_drop: false }`
[INFO] [stdout] 47402eb392da67f5adb2cf53e8bbcd53422c9f500aa46d029d913722a7b62b8f
