[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 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffisherdarling%2Fmaze_project" "/workspace/builds/worker-24/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-24/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fisherdarling/maze_project on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-24/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" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded derive_more v0.99.2
[INFO] [stderr]   Downloaded text_io v0.1.7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-24/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-24/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f941826bd659a13bac28528f1994f411de220c67704dfbe7d96a1b095729a7d9
[INFO] running `Command { std: "docker" "start" "-a" "f941826bd659a13bac28528f1994f411de220c67704dfbe7d96a1b095729a7d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f941826bd659a13bac28528f1994f411de220c67704dfbe7d96a1b095729a7d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f941826bd659a13bac28528f1994f411de220c67704dfbe7d96a1b095729a7d9", kill_on_drop: false }`
[INFO] [stdout] f941826bd659a13bac28528f1994f411de220c67704dfbe7d96a1b095729a7d9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-24/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-24/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 03682b3c982496e5444cc4a1722de046ea9d3b723556632e01b3821cb84a4794
[INFO] running `Command { std: "docker" "start" "-a" "03682b3c982496e5444cc4a1722de046ea9d3b723556632e01b3821cb84a4794", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.6
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]     Checking ordermap v0.3.5
[INFO] [stderr]     Checking fixedbitset v0.1.9
[INFO] [stderr]     Checking text_io v0.1.7
[INFO] [stderr]     Checking petgraph v0.4.13
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling derive_more v0.99.2
[INFO] [stderr]  Documenting maze_project v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking maze_project v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/bin/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(slice_concat_trait)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^
[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 E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `maze_project`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[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,artifacts,future-incompat --document-private-items -C metadata=02d651a35b0756c6 -L dependency=/opt/rustwide/target/debug/deps --extern derive_more=/opt/rustwide/target/debug/deps/libderive_more-eeb2127a0ac4374b.so --extern maze_project=/opt/rustwide/target/debug/deps/libmaze_project-3e4ba5d18b46082b.rmeta --extern petgraph=/opt/rustwide/target/debug/deps/libpetgraph-0fee134ff3fc8849.rmeta --extern text_io=/opt/rustwide/target/debug/deps/libtext_io-8d94e17c4b32a2da.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "03682b3c982496e5444cc4a1722de046ea9d3b723556632e01b3821cb84a4794", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03682b3c982496e5444cc4a1722de046ea9d3b723556632e01b3821cb84a4794", kill_on_drop: false }`
[INFO] [stdout] 03682b3c982496e5444cc4a1722de046ea9d3b723556632e01b3821cb84a4794