[INFO] cloning repository https://github.com/JoshuaPostel/rust-book-hello
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/JoshuaPostel/rust-book-hello" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJoshuaPostel%2Frust-book-hello", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJoshuaPostel%2Frust-book-hello'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7da319d05625958f4a890346362d7db0540ebbaf
[INFO] documenting JoshuaPostel/rust-book-hello 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%2FJoshuaPostel%2Frust-book-hello" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/JoshuaPostel/rust-book-hello 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/JoshuaPostel/rust-book-hello
[INFO] finished tweaking git repo https://github.com/JoshuaPostel/rust-book-hello
[INFO] tweaked toml for git repo https://github.com/JoshuaPostel/rust-book-hello written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/JoshuaPostel/rust-book-hello 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] da690983198262b2d909e1ae1fccdaf5b8ef76fa10f6517cd07285ac9b42ae60
[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" "da690983198262b2d909e1ae1fccdaf5b8ef76fa10f6517cd07285ac9b42ae60", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "da690983198262b2d909e1ae1fccdaf5b8ef76fa10f6517cd07285ac9b42ae60", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da690983198262b2d909e1ae1fccdaf5b8ef76fa10f6517cd07285ac9b42ae60", kill_on_drop: false }`
[INFO] [stdout] da690983198262b2d909e1ae1fccdaf5b8ef76fa10f6517cd07285ac9b42ae60
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] [stdout] b878016ee3f8fc920d33044bee0e5f839406c2857ec680fe6b4bcd30098fa9d2
[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" "b878016ee3f8fc920d33044bee0e5f839406c2857ec680fe6b4bcd30098fa9d2", kill_on_drop: false }`
[INFO] [stderr]     Checking hello v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting hello v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0599]: no method named `join` found for enum `std::option::Option<std::thread::JoinHandle<()>>` in the current scope
[INFO] [stdout]   --> src/lib.rs:60:27
[INFO] [stdout]    |
[INFO] [stdout] 60 |             worker.thread.join().unwrap();
[INFO] [stdout]    |                           ^^^^ method not found in `std::option::Option<std::thread::JoinHandle<()>>`
[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 E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hello`.
[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" "b878016ee3f8fc920d33044bee0e5f839406c2857ec680fe6b4bcd30098fa9d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b878016ee3f8fc920d33044bee0e5f839406c2857ec680fe6b4bcd30098fa9d2", kill_on_drop: false }`
[INFO] [stdout] b878016ee3f8fc920d33044bee0e5f839406c2857ec680fe6b4bcd30098fa9d2