[INFO] fetching crate geen 0.0.7...
[INFO] documenting geen-0.0.7 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate geen 0.0.7 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate geen 0.0.7 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate geen 0.0.7
[INFO] finished tweaking crates.io crate geen 0.0.7
[INFO] tweaked toml for crates.io crate geen 0.0.7 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded mohan v0.0.53
[INFO] [stderr]   Downloaded croaring v0.3.9
[INFO] [stderr]   Downloaded croaring-sys v0.3.9
[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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2860c9a46e7db83950ae3a1f61c7e45afcfe7167fdccd39ca6b6deb710a28560
[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" "2860c9a46e7db83950ae3a1f61c7e45afcfe7167fdccd39ca6b6deb710a28560", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2860c9a46e7db83950ae3a1f61c7e45afcfe7167fdccd39ca6b6deb710a28560", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2860c9a46e7db83950ae3a1f61c7e45afcfe7167fdccd39ca6b6deb710a28560", kill_on_drop: false }`
[INFO] [stdout] 2860c9a46e7db83950ae3a1f61c7e45afcfe7167fdccd39ca6b6deb710a28560
[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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8c666fae1bbef80be812599e766262a679716f1a52cef497fb6bd27bd01afd48
[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" "8c666fae1bbef80be812599e766262a679716f1a52cef497fb6bd27bd01afd48", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling packed_simd v0.3.3
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]     Checking subtle v2.2.3
[INFO] [stderr]    Compiling hashbrown v0.6.3
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]     Checking backtrace v0.3.50
[INFO] [stderr]     Checking thread-id v3.3.0
[INFO] [stderr]    Compiling thiserror-impl v1.0.20
[INFO] [stderr]     Checking digest v0.8.1
[INFO] [stderr]    Compiling zeroize_derive v1.0.0
[INFO] [stderr]    Compiling bindgen v0.37.4
[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-2.2.3/src/lib.rs:12:34
[INFO] [stdout]    |
[INFO] [stdout] 12 | #![cfg_attr(feature = "nightly", feature(external_doc))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [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" "8c666fae1bbef80be812599e766262a679716f1a52cef497fb6bd27bd01afd48", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c666fae1bbef80be812599e766262a679716f1a52cef497fb6bd27bd01afd48", kill_on_drop: false }`
[INFO] [stdout] 8c666fae1bbef80be812599e766262a679716f1a52cef497fb6bd27bd01afd48