[INFO] fetching crate bruteforce 0.2.0...
[INFO] documenting bruteforce-0.2.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate bruteforce 0.2.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate bruteforce 0.2.0 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 crates.io crate bruteforce 0.2.0
[INFO] finished tweaking crates.io crate bruteforce 0.2.0
[INFO] tweaked toml for crates.io crate bruteforce 0.2.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] d9c80d4dc57c7ce24c15fe915e9bd9b8f89cef5a62a299fd1ea3fdf3425c54cb
[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" "d9c80d4dc57c7ce24c15fe915e9bd9b8f89cef5a62a299fd1ea3fdf3425c54cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d9c80d4dc57c7ce24c15fe915e9bd9b8f89cef5a62a299fd1ea3fdf3425c54cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d9c80d4dc57c7ce24c15fe915e9bd9b8f89cef5a62a299fd1ea3fdf3425c54cb", kill_on_drop: false }`
[INFO] [stdout] d9c80d4dc57c7ce24c15fe915e9bd9b8f89cef5a62a299fd1ea3fdf3425c54cb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] b1b4c6335020aa57a1e5f105f3e77d0a19c63c5a581149b29f01c28cc893560e
[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" "b1b4c6335020aa57a1e5f105f3e77d0a19c63c5a581149b29f01c28cc893560e", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling no-std-compat v0.3.0
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling bruteforce-macros v0.2.0
[INFO] [stderr]  Documenting bruteforce v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:4:1
[INFO] [stdout]    |
[INFO] [stdout] 4  | / #![feature(
[INFO] [stdout] 5  | |     const_fn,
[INFO] [stdout] 6  | |     test,
[INFO] [stdout] 7  | |     generators,
[INFO] [stdout] ...  |
[INFO] [stdout] 11 | |     proc_macro_hygiene
[INFO] [stdout] 12 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `bruteforce`.
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name bruteforce src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="bruteforce-macros"' --cfg 'feature="constants"' --cfg 'feature="default"' --cfg 'feature="std"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern bruteforce_macros=/opt/rustwide/target/debug/deps/libbruteforce_macros-4b619ec2fc4efe19.so --extern no_std_compat=/opt/rustwide/target/debug/deps/libno_std_compat-4ee2e296e58e7167.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "b1b4c6335020aa57a1e5f105f3e77d0a19c63c5a581149b29f01c28cc893560e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b1b4c6335020aa57a1e5f105f3e77d0a19c63c5a581149b29f01c28cc893560e", kill_on_drop: false }`
[INFO] [stdout] b1b4c6335020aa57a1e5f105f3e77d0a19c63c5a581149b29f01c28cc893560e