[INFO] fetching crate pattern-3 0.5.0...
[INFO] documenting pattern-3-0.5.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate pattern-3 0.5.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate pattern-3 0.5.0 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 pattern-3 0.5.0
[INFO] finished tweaking crates.io crate pattern-3 0.5.0
[INFO] tweaked toml for crates.io crate pattern-3 0.5.0 written to /workspace/builds/worker-14/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] 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-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 2737d44c6fa2d1af67b0f60aed0e0edfacafe2b15123a7da37e56bda7d10b4c2
[INFO] running `Command { std: "docker" "start" "-a" "2737d44c6fa2d1af67b0f60aed0e0edfacafe2b15123a7da37e56bda7d10b4c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2737d44c6fa2d1af67b0f60aed0e0edfacafe2b15123a7da37e56bda7d10b4c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2737d44c6fa2d1af67b0f60aed0e0edfacafe2b15123a7da37e56bda7d10b4c2", kill_on_drop: false }`
[INFO] [stdout] 2737d44c6fa2d1af67b0f60aed0e0edfacafe2b15123a7da37e56bda7d10b4c2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 2300d54e4ba75f82c5e623f6cf54295217599100875f2c72179e659403995cf4
[INFO] running `Command { std: "docker" "start" "-a" "2300d54e4ba75f82c5e623f6cf54295217599100875f2c72179e659403995cf4", kill_on_drop: false }`
[INFO] [stderr]  Documenting pattern-3 v0.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:1:1
[INFO] [stdout]    |
[INFO] [stdout] 1  | / #![feature(
[INFO] [stdout] 2  | |     specialization,
[INFO] [stdout] 3  | |     // used in two places:
[INFO] [stdout] 4  | |     //  1. to support using the same two-way algorithm for non-Ord slices
[INFO] [stdout] ...  |
[INFO] [stdout] 17 | |     // some useful library features
[INFO] [stdout] 18 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `pattern-3`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name pattern_3 src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="std"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern libc=/opt/rustwide/target/debug/deps/liblibc-1ad3ad1e20beb97f.rmeta --extern memchr=/opt/rustwide/target/debug/deps/libmemchr-627133d374ce1598.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "2300d54e4ba75f82c5e623f6cf54295217599100875f2c72179e659403995cf4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2300d54e4ba75f82c5e623f6cf54295217599100875f2c72179e659403995cf4", kill_on_drop: false }`
[INFO] [stdout] 2300d54e4ba75f82c5e623f6cf54295217599100875f2c72179e659403995cf4