[INFO] cloning repository https://github.com/darkwater/um
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/darkwater/um" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdarkwater%2Fum", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdarkwater%2Fum'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 290006bff8a85d175e37e16f89eb0fa19b9114ad
[INFO] documenting darkwater/um against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdarkwater%2Fum" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/darkwater/um 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 git repo https://github.com/darkwater/um
[INFO] finished tweaking git repo https://github.com/darkwater/um
[INFO] tweaked toml for git repo https://github.com/darkwater/um written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/darkwater/um 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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] e7a2264707356e701174e57d17ce56d921a1d4f343d231cc8e53f723dc6efadc
[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" "e7a2264707356e701174e57d17ce56d921a1d4f343d231cc8e53f723dc6efadc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e7a2264707356e701174e57d17ce56d921a1d4f343d231cc8e53f723dc6efadc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e7a2264707356e701174e57d17ce56d921a1d4f343d231cc8e53f723dc6efadc", kill_on_drop: false }`
[INFO] [stdout] e7a2264707356e701174e57d17ce56d921a1d4f343d231cc8e53f723dc6efadc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7e79018a0e307957fd9b958d7daf52b666680f2896a28707dcec0b350ea91839
[INFO] running `Command { std: "docker" "start" "-a" "7e79018a0e307957fd9b958d7daf52b666680f2896a28707dcec0b350ea91839", kill_on_drop: false }`
[INFO] [stderr]     Checking futures v0.1.20
[INFO] [stderr]     Checking bytes v0.4.6
[INFO] [stderr]     Checking crossbeam-deque v0.3.0
[INFO] [stderr]     Checking tokio-executor v0.1.1
[INFO] [stderr]     Checking tokio-io v0.1.6
[INFO] [stderr]     Checking tokio-threadpool v0.1.1
[INFO] [stderr]     Checking tokio-reactor v0.1.1
[INFO] [stderr]     Checking tokio-udp v0.1.0
[INFO] [stderr]     Checking tokio-tcp v0.1.0
[INFO] [stderr]     Checking tokio v0.1.4
[INFO] [stderr]  Documenting um v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(match_default_bindings, nll, option_filter, try_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `um`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name um src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern bytes=/opt/rustwide/target/debug/deps/libbytes-6fa1556d43ba55f9.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-419344601ee0806d.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-5174920e8e8bb36d.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "7e79018a0e307957fd9b958d7daf52b666680f2896a28707dcec0b350ea91839", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7e79018a0e307957fd9b958d7daf52b666680f2896a28707dcec0b350ea91839", kill_on_drop: false }`
[INFO] [stdout] 7e79018a0e307957fd9b958d7daf52b666680f2896a28707dcec0b350ea91839