[INFO] fetching crate mdbook 0.4.2...
[INFO] documenting mdbook-0.4.2 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate mdbook 0.4.2 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate mdbook 0.4.2 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 mdbook 0.4.2
[INFO] finished tweaking crates.io crate mdbook 0.4.2
[INFO] tweaked toml for crates.io crate mdbook 0.4.2 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate crates.io crate mdbook 0.4.2 already has a lockfile, it will not be regenerated
[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]     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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f7e3aa7ffb011647e8037a70492dce94425a773db694fd3998698a8799e32992
[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" "f7e3aa7ffb011647e8037a70492dce94425a773db694fd3998698a8799e32992", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f7e3aa7ffb011647e8037a70492dce94425a773db694fd3998698a8799e32992", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f7e3aa7ffb011647e8037a70492dce94425a773db694fd3998698a8799e32992", kill_on_drop: false }`
[INFO] [stdout] f7e3aa7ffb011647e8037a70492dce94425a773db694fd3998698a8799e32992
[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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f08f238f6be9f0e9dcbe368d116d15e31d2c24c806fa21985f1ffe7079c833e6
[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" "f08f238f6be9f0e9dcbe368d116d15e31d2c24c806fa21985f1ffe7079c833e6", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.17
[INFO] [stderr]    Compiling pulldown-cmark v0.7.0
[INFO] [stderr]     Checking base64 v0.12.0
[INFO] [stderr]     Checking urlencoding v1.0.0
[INFO] [stderr]     Checking input_buffer v0.3.1
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]     Checking headers-core v0.2.0
[INFO] [stderr]     Checking http-body v0.3.1
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking filetime v0.2.9
[INFO] [stderr]    Compiling serde_json v1.0.52
[INFO] [stderr]     Checking want v0.3.0
[INFO] [stderr]     Checking serde_urlencoded v0.6.1
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking rand_pcg v0.2.1
[INFO] [stderr]     Checking chrono v0.4.11
[INFO] [stderr]     Checking mime_guess v2.0.3
[INFO] [stderr]     Checking inotify v0.7.0
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking headers v0.3.2
[INFO] [stderr]     Checking notify v4.0.15
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]     Checking tungstenite v0.10.1
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling phf_generator v0.8.0
[INFO] [stderr]    Compiling phf_codegen v0.8.0
[INFO] [stderr]    Compiling string_cache_codegen v0.5.1
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]    Compiling serde_derive v1.0.106
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling pin-project-internal v0.4.9
[INFO] [stderr]    Compiling html5ever v0.25.1
[INFO] [stderr]    Compiling strum_macros v0.16.0
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]     Checking handlebars v3.0.1
[INFO] [stderr]     Checking tokio v0.2.18
[INFO] [stderr]     Checking futures-util v0.3.4
[INFO] [stderr]     Checking pin-project v0.4.9
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]     Checking futures-executor v0.3.4
[INFO] [stderr]     Checking h2 v0.2.4
[INFO] [stderr]     Checking futures v0.3.4
[INFO] [stderr]     Checking tokio-tungstenite v0.10.1
[INFO] [stderr]    Compiling markup5ever v0.10.0
[INFO] [stderr]     Checking elasticlunr-rs v2.3.8
[INFO] [stderr]     Checking hyper v0.13.5
[INFO] [stderr]     Checking xml5ever v0.16.1
[INFO] [stderr]     Checking warp v0.2.2
[INFO] [stderr]     Checking markup5ever_rcdom v0.1.0
[INFO] [stderr]     Checking ammonia v3.1.0
[INFO] [stderr]  Documenting mdbook v0.4.2 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1m 41s
[INFO] running `Command { std: "docker" "inspect" "f08f238f6be9f0e9dcbe368d116d15e31d2c24c806fa21985f1ffe7079c833e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f08f238f6be9f0e9dcbe368d116d15e31d2c24c806fa21985f1ffe7079c833e6", kill_on_drop: false }`
[INFO] [stdout] f08f238f6be9f0e9dcbe368d116d15e31d2c24c806fa21985f1ffe7079c833e6