[INFO] fetching crate balloon 0.0.10...
[INFO] documenting balloon-0.0.10 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate balloon 0.0.10 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate balloon 0.0.10 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 balloon 0.0.10
[INFO] finished tweaking crates.io crate balloon 0.0.10
[INFO] tweaked toml for crates.io crate balloon 0.0.10 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "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" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] bd658db96df9992dce2954b95dbac7b681ba6ba0da804cefa229a48c6c98b7df
[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" "bd658db96df9992dce2954b95dbac7b681ba6ba0da804cefa229a48c6c98b7df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bd658db96df9992dce2954b95dbac7b681ba6ba0da804cefa229a48c6c98b7df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bd658db96df9992dce2954b95dbac7b681ba6ba0da804cefa229a48c6c98b7df", kill_on_drop: false }`
[INFO] [stdout] bd658db96df9992dce2954b95dbac7b681ba6ba0da804cefa229a48c6c98b7df
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 5a931db3cf64d834a5ac1a37e1c62f4f0acc509464941c8828a7ca09e8b20558
[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" "5a931db3cf64d834a5ac1a37e1c62f4f0acc509464941c8828a7ca09e8b20558", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]     Checking fixedbitset v0.2.0
[INFO] [stderr]    Compiling packed_simd v0.3.3
[INFO] [stderr]     Checking static_assertions v1.1.0
[INFO] [stderr]     Checking constant_time_eq v0.1.5
[INFO] [stderr]     Checking rustc-hex v2.1.0
[INFO] [stderr]     Checking arrayvec v0.5.1
[INFO] [stderr]    Compiling num-bigint-dig v0.4.0
[INFO] [stderr]     Checking subtle v2.2.3
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking thread-id v3.3.0
[INFO] [stderr]     Checking smallvec v0.6.13
[INFO] [stderr]     Checking digest v0.8.1
[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/subtle-2.2.3/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 thiserror-impl v1.0.20
[INFO] [stderr]     Checking crossbeam v0.7.3
[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" "5a931db3cf64d834a5ac1a37e1c62f4f0acc509464941c8828a7ca09e8b20558", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5a931db3cf64d834a5ac1a37e1c62f4f0acc509464941c8828a7ca09e8b20558", kill_on_drop: false }`
[INFO] [stdout] 5a931db3cf64d834a5ac1a37e1c62f4f0acc509464941c8828a7ca09e8b20558