[INFO] cloning repository https://github.com/chessai/union-find
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/chessai/union-find" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchessai%2Funion-find", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchessai%2Funion-find'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 983ff4dd177b49dd1a160d6a88b402c264b4d43b
[INFO] documenting chessai/union-find 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%2Fchessai%2Funion-find" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/chessai/union-find 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/chessai/union-find
[INFO] finished tweaking git repo https://github.com/chessai/union-find
[INFO] tweaked toml for git repo https://github.com/chessai/union-find written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/chessai/union-find 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 bencher v0.1.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] c56eb116ad5759fc3c8677f96e9869ad3d01acb1868e85d7834bba986bed86ea
[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" "c56eb116ad5759fc3c8677f96e9869ad3d01acb1868e85d7834bba986bed86ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c56eb116ad5759fc3c8677f96e9869ad3d01acb1868e85d7834bba986bed86ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c56eb116ad5759fc3c8677f96e9869ad3d01acb1868e85d7834bba986bed86ea", kill_on_drop: false }`
[INFO] [stdout] c56eb116ad5759fc3c8677f96e9869ad3d01acb1868e85d7834bba986bed86ea
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] de284d524c8f1e2290305f49a1ee162ca3646531a5611f44587f80df03c5968d
[INFO] running `Command { std: "docker" "start" "-a" "de284d524c8f1e2290305f49a1ee162ca3646531a5611f44587f80df03c5968d", kill_on_drop: false }`
[INFO] [stderr]     Checking bencher v0.1.5
[INFO] [stderr]  Documenting union-find 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:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(test)]
[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 `union-find`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name union_find src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=563905260dd308a2 -L dependency=/opt/rustwide/target/debug/deps --extern bencher=/opt/rustwide/target/debug/deps/libbencher-ad8991fc2bc653f2.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "de284d524c8f1e2290305f49a1ee162ca3646531a5611f44587f80df03c5968d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "de284d524c8f1e2290305f49a1ee162ca3646531a5611f44587f80df03c5968d", kill_on_drop: false }`
[INFO] [stdout] de284d524c8f1e2290305f49a1ee162ca3646531a5611f44587f80df03c5968d