[INFO] cloning repository https://github.com/fisherdarling/maze_project
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fisherdarling/maze_project" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffisherdarling%2Fmaze_project", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffisherdarling%2Fmaze_project'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c83fd51e56f360143ddfa4fdd77e492e100b5b42
[INFO] documenting fisherdarling/maze_project 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%2Ffisherdarling%2Fmaze_project" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fisherdarling/maze_project 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/fisherdarling/maze_project
[INFO] finished tweaking git repo https://github.com/fisherdarling/maze_project
[INFO] tweaked toml for git repo https://github.com/fisherdarling/maze_project written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/fisherdarling/maze_project 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] 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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f581195c77aaacb76ad85c720a92aad385b492f702fbeee9ad83086441596f52
[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" "f581195c77aaacb76ad85c720a92aad385b492f702fbeee9ad83086441596f52", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f581195c77aaacb76ad85c720a92aad385b492f702fbeee9ad83086441596f52", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f581195c77aaacb76ad85c720a92aad385b492f702fbeee9ad83086441596f52", kill_on_drop: false }`
[INFO] [stdout] f581195c77aaacb76ad85c720a92aad385b492f702fbeee9ad83086441596f52
[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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d9c02a06ab9f674ae68f952b92226e68ef7f4feaf11bf6034d48787b188daaad
[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" "d9c02a06ab9f674ae68f952b92226e68ef7f4feaf11bf6034d48787b188daaad", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling derive_more v0.99.2
[INFO] [stderr]     Checking maze_project v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting maze_project v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: Could not document `maze_project`.
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/bin/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(slice_concat_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] Caused by:
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name main src/bin/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 derive_more=/opt/rustwide/target/debug/deps/libderive_more-6ab4c8708d35733a.so --extern maze_project=/opt/rustwide/target/debug/deps/libmaze_project-c23661ed6e6aa086.rmeta --extern petgraph=/opt/rustwide/target/debug/deps/libpetgraph-2849dc170b4d8716.rmeta --extern text_io=/opt/rustwide/target/debug/deps/libtext_io-93b5498eb4a0bfd1.rmeta --cap-lints=warn` (exit code: 1)
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "d9c02a06ab9f674ae68f952b92226e68ef7f4feaf11bf6034d48787b188daaad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d9c02a06ab9f674ae68f952b92226e68ef7f4feaf11bf6034d48787b188daaad", kill_on_drop: false }`
[INFO] [stdout] d9c02a06ab9f674ae68f952b92226e68ef7f4feaf11bf6034d48787b188daaad