[INFO] fetching crate mech 0.0.5...
[INFO] documenting mech-0.0.5 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate mech 0.0.5 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate mech 0.0.5 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mech 0.0.5
[INFO] finished tweaking crates.io crate mech 0.0.5
[INFO] tweaked toml for crates.io crate mech 0.0.5 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate crates.io crate mech 0.0.5 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", 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] 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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e2c3f520f9a99d3f953fd56cb7847eb88446d4d4c3402079117c7c8ce4456215
[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" "e2c3f520f9a99d3f953fd56cb7847eb88446d4d4c3402079117c7c8ce4456215", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e2c3f520f9a99d3f953fd56cb7847eb88446d4d4c3402079117c7c8ce4456215", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2c3f520f9a99d3f953fd56cb7847eb88446d4d4c3402079117c7c8ce4456215", kill_on_drop: false }`
[INFO] [stdout] e2c3f520f9a99d3f953fd56cb7847eb88446d4d4c3402079117c7c8ce4456215
[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" "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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] acb2ac2d29afc072df9c0e696a60d9c110923a1f0ed4a20b70d359f4baeff120
[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" "acb2ac2d29afc072df9c0e696a60d9c110923a1f0ed4a20b70d359f4baeff120", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]     Checking once_cell v1.3.1
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]     Checking ahash v0.3.4
[INFO] [stderr]     Checking static_assertions v0.3.4
[INFO] [stderr]     Checking bytestring v0.1.5
[INFO] [stderr]     Checking input_buffer v0.3.1
[INFO] [stderr]    Compiling backtrace-sys v0.1.37
[INFO] [stderr]    Compiling brotli-sys v0.3.2
[INFO] [stderr]    Compiling ring v0.16.13
[INFO] [stderr]    Compiling hashbrown v0.7.2
[INFO] [stderr]    Compiling error-chain v0.12.2
[INFO] [stderr]    Compiling nom v5.1.1
[INFO] [stderr]    Compiling openssl-sys v0.9.55
[INFO] [stderr]     Checking idna v0.1.5
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.34
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]     Checking time v0.1.43
[INFO] [stderr]     Checking parking_lot_core v0.7.2
[INFO] [stderr]     Checking hostname v0.3.1
[INFO] [stderr]     Checking socket2 v0.3.12
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]    Compiling lexical-core v0.6.2
[INFO] [stderr]     Checking flate2 v1.0.14
[INFO] [stderr]     Checking threadpool v1.8.0
[INFO] [stderr]     Checking futures-cpupool v0.1.8
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking colored v1.9.3
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking resolv-conf v0.6.3
[INFO] [stderr]     Checking parking_lot v0.10.2
[INFO] [stderr]     Checking rand v0.6.5
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking mio v0.6.22
[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/hashbrown-0.7.2/src/lib.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | /     feature(
[INFO] [stdout] 16 | |         alloc_layout_extra,
[INFO] [stdout] 17 | |         allocator_api,
[INFO] [stdout] 18 | |         ptr_offset_from,
[INFO] [stdout] ...  |
[INFO] [stdout] 22 | |         specialization,
[INFO] [stdout] 23 | |     )
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking chrono v0.4.11
[INFO] [stderr]     Checking tokio-threadpool v0.1.18
[INFO] [stderr]     Checking publicsuffix v1.5.4
[INFO] [stderr]     Checking parking_lot v0.9.0
[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 `hashbrown`.
[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" "acb2ac2d29afc072df9c0e696a60d9c110923a1f0ed4a20b70d359f4baeff120", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acb2ac2d29afc072df9c0e696a60d9c110923a1f0ed4a20b70d359f4baeff120", kill_on_drop: false }`
[INFO] [stdout] acb2ac2d29afc072df9c0e696a60d9c110923a1f0ed4a20b70d359f4baeff120