[INFO] fetching crate mut_guard 0.1.0...
[INFO] documenting mut_guard-0.1.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate mut_guard 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate mut_guard 0.1.0 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 mut_guard 0.1.0
[INFO] finished tweaking crates.io crate mut_guard 0.1.0
[INFO] tweaked toml for crates.io crate mut_guard 0.1.0 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] 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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 969f6711dd805eaaa3352021ab0bec667971ca2caa7e618d50f816c5202d6450
[INFO] running `Command { std: "docker" "start" "-a" "969f6711dd805eaaa3352021ab0bec667971ca2caa7e618d50f816c5202d6450", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "969f6711dd805eaaa3352021ab0bec667971ca2caa7e618d50f816c5202d6450", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "969f6711dd805eaaa3352021ab0bec667971ca2caa7e618d50f816c5202d6450", kill_on_drop: false }`
[INFO] [stdout] 969f6711dd805eaaa3352021ab0bec667971ca2caa7e618d50f816c5202d6450
[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] e860a54cbb638d24b09cb4bb37df1c788981d9deedf996248b3056324ba34bf9
[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" "e860a54cbb638d24b09cb4bb37df1c788981d9deedf996248b3056324ba34bf9", kill_on_drop: false }`
[INFO] [stderr]  Documenting mut_guard v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.67s
[INFO] running `Command { std: "docker" "inspect" "e860a54cbb638d24b09cb4bb37df1c788981d9deedf996248b3056324ba34bf9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e860a54cbb638d24b09cb4bb37df1c788981d9deedf996248b3056324ba34bf9", kill_on_drop: false }`
[INFO] [stdout] e860a54cbb638d24b09cb4bb37df1c788981d9deedf996248b3056324ba34bf9