[INFO] fetching crate cow 0.0.8...
[INFO] documenting cow-0.0.8 against master#394e1b40d264aa6928811919c1124fa248e7d802 for pr-73566
[INFO] extracting crate cow 0.0.8 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate cow 0.0.8 on toolchain 394e1b40d264aa6928811919c1124fa248e7d802
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cow 0.0.8
[INFO] finished tweaking crates.io crate cow 0.0.8
[INFO] tweaked toml for crates.io crate cow 0.0.8 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "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" "+394e1b40d264aa6928811919c1124fa248e7d802" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: path `/workspace/builds/worker-4/source/src/cow.rs` was erroneously implicitly accepted for library `cow`,
[INFO] [stderr] please rename the file to `src/lib.rs` or set lib.path in Cargo.toml
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8fd14e19757e3b72c9e9642864aff003b9fa957327c5463adce4b822e55c07de
[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" "8fd14e19757e3b72c9e9642864aff003b9fa957327c5463adce4b822e55c07de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8fd14e19757e3b72c9e9642864aff003b9fa957327c5463adce4b822e55c07de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8fd14e19757e3b72c9e9642864aff003b9fa957327c5463adce4b822e55c07de", kill_on_drop: false }`
[INFO] [stdout] 8fd14e19757e3b72c9e9642864aff003b9fa957327c5463adce4b822e55c07de
[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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 88ee8b9c2c05dd939807663069b8f59eef7e22602e3ba4ff13bdcea70f3b7c4e
[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" "88ee8b9c2c05dd939807663069b8f59eef7e22602e3ba4ff13bdcea70f3b7c4e", kill_on_drop: false }`
[INFO] [stderr] warning: path `/opt/rustwide/workdir/src/cow.rs` was erroneously implicitly accepted for library `cow`,
[INFO] [stderr] please rename the file to `src/lib.rs` or set lib.path in Cargo.toml
[INFO] [stderr]  Documenting cow v0.0.8 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0463]: can't find crate for `collections`
[INFO] [stdout]  --> src/cow.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | extern crate collections;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `cow`.
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name cow src/cow.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern rustc_serialize=/opt/rustwide/target/debug/deps/librustc_serialize-7ddf6b4d13e0395e.rmeta --cap-lints=forbid` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "88ee8b9c2c05dd939807663069b8f59eef7e22602e3ba4ff13bdcea70f3b7c4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "88ee8b9c2c05dd939807663069b8f59eef7e22602e3ba4ff13bdcea70f3b7c4e", kill_on_drop: false }`
[INFO] [stdout] 88ee8b9c2c05dd939807663069b8f59eef7e22602e3ba4ff13bdcea70f3b7c4e