[INFO] cloning repository https://github.com/Knight-Ops/advent-of-code-2021
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Knight-Ops/advent-of-code-2021" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FKnight-Ops%2Fadvent-of-code-2021", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FKnight-Ops%2Fadvent-of-code-2021'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6431bf9245bbd641bb9f615abd7ad4919f228364
[INFO] documenting Knight-Ops/advent-of-code-2021 against 1.69.0 for beta-1.70-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FKnight-Ops%2Fadvent-of-code-2021" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Knight-Ops/advent-of-code-2021 on toolchain 1.69.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.69.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Knight-Ops/advent-of-code-2021
[INFO] finished tweaking git repo https://github.com/Knight-Ops/advent-of-code-2021
[INFO] tweaked toml for git repo https://github.com/Knight-Ops/advent-of-code-2021 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Knight-Ops/advent-of-code-2021 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.69.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+1.69.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 62af03ee6bcd138a4f7cd6235c5e0b590dd079baeb64181e594c1eea6ebef305
[INFO] running `Command { std: "docker" "start" "-a" "62af03ee6bcd138a4f7cd6235c5e0b590dd079baeb64181e594c1eea6ebef305", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "62af03ee6bcd138a4f7cd6235c5e0b590dd079baeb64181e594c1eea6ebef305", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "62af03ee6bcd138a4f7cd6235c5e0b590dd079baeb64181e594c1eea6ebef305", kill_on_drop: false }`
[INFO] [stdout] 62af03ee6bcd138a4f7cd6235c5e0b590dd079baeb64181e594c1eea6ebef305
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "RUSTFLAGS=--cap-lints=warn" "-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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+1.69.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1e9fd48e11e678293240520f88b4dd0e36c40056fae3d740e37c6b54c8ec443c
[INFO] running `Command { std: "docker" "start" "-a" "1e9fd48e11e678293240520f88b4dd0e36c40056fae3d740e37c6b54c8ec443c", kill_on_drop: false }`
[INFO] [stderr]  Documenting advent-of-code-2021 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(hash_drain_filter)]
[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 `advent-of-code-2021`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2021 --crate-type lib --crate-name advent_of_code_2021 src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=c1d6f83c32296bf4 -L dependency=/opt/rustwide/target/debug/deps --extern fnv=/opt/rustwide/target/debug/deps/libfnv-df36d14af7528695.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-9c7d51f549cf58b7.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "1e9fd48e11e678293240520f88b4dd0e36c40056fae3d740e37c6b54c8ec443c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e9fd48e11e678293240520f88b4dd0e36c40056fae3d740e37c6b54c8ec443c", kill_on_drop: false }`
[INFO] [stdout] 1e9fd48e11e678293240520f88b4dd0e36c40056fae3d740e37c6b54c8ec443c
