[INFO] fetching crate crystal_ball 0.2.0...
[INFO] documenting crystal_ball-0.2.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate crystal_ball 0.2.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate crystal_ball 0.2.0 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 crates.io crate crystal_ball 0.2.0
[INFO] finished tweaking crates.io crate crystal_ball 0.2.0
[INFO] tweaked toml for crates.io crate crystal_ball 0.2.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate crystal_ball 0.2.0 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]  Downloading crates ...
[INFO] [stderr]   Downloaded nanorand v0.5.2
[INFO] [stderr]   Downloaded indicatif v0.16.0
[INFO] [stderr]   Downloaded oidn v1.3.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7ba44e98d0c61e35d631230e7a1e08f3497227b44a392f5d4a63ed762bdb47d8
[INFO] running `Command { std: "docker" "start" "-a" "7ba44e98d0c61e35d631230e7a1e08f3497227b44a392f5d4a63ed762bdb47d8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7ba44e98d0c61e35d631230e7a1e08f3497227b44a392f5d4a63ed762bdb47d8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7ba44e98d0c61e35d631230e7a1e08f3497227b44a392f5d4a63ed762bdb47d8", kill_on_drop: false }`
[INFO] [stdout] 7ba44e98d0c61e35d631230e7a1e08f3497227b44a392f5d4a63ed762bdb47d8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] ba2362e648f90edb03f73ce9d2eb55887e7ff57330176265453bf8f17f55d2a7
[INFO] running `Command { std: "docker" "start" "-a" "ba2362e648f90edb03f73ce9d2eb55887e7ff57330176265453bf8f17f55d2a7", kill_on_drop: false }`
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling libc v0.2.94
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]     Checking adler32 v1.2.0
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking weezl v0.1.5
[INFO] [stderr]     Checking adler v1.0.2
[INFO] [stderr]     Checking color_quant v1.1.0
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking number_prefix v0.4.0
[INFO] [stderr]     Checking bytemuck v1.5.1
[INFO] [stderr]     Checking scoped_threadpool v0.1.9
[INFO] [stderr]     Checking nanorand v0.5.2
[INFO] [stderr]    Compiling crossbeam-utils v0.8.4
[INFO] [stderr]    Compiling memoffset v0.6.3
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-rational v0.3.2
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling crc32fast v1.2.1
[INFO] [stderr]     Checking miniz_oxide v0.3.7
[INFO] [stderr]     Checking deflate v0.8.6
[INFO] [stderr]     Checking gif v0.11.2
[INFO] [stderr]     Checking png v0.16.8
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking terminal_size v0.1.16
[INFO] [stderr]     Checking crossbeam-epoch v0.9.4
[INFO] [stderr]     Checking crossbeam-channel v0.5.1
[INFO] [stderr]     Checking crossbeam-deque v0.8.0
[INFO] [stderr]     Checking console v0.14.1
[INFO] [stderr]     Checking indicatif v0.16.0
[INFO] [stderr]     Checking jpeg-decoder v0.1.22
[INFO] [stderr]     Checking tiff v0.6.1
[INFO] [stderr]     Checking image v0.23.14
[INFO] [stderr]  Documenting crystal_ball 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:1:18
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(doc, feature(doc_cfg))]
[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 `crystal_ball`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name crystal_ball src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=8c7fa3e0d4ef33e1 -L dependency=/opt/rustwide/target/debug/deps --extern image=/opt/rustwide/target/debug/deps/libimage-20d14e8ff2279533.rmeta --extern indicatif=/opt/rustwide/target/debug/deps/libindicatif-b98567d932296732.rmeta --extern nanorand=/opt/rustwide/target/debug/deps/libnanorand-4c18be0dd38c9bae.rmeta --extern rayon=/opt/rustwide/target/debug/deps/librayon-dc910378c160d45b.rmeta --cap-lints=warn --crate-version 0.2.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "ba2362e648f90edb03f73ce9d2eb55887e7ff57330176265453bf8f17f55d2a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba2362e648f90edb03f73ce9d2eb55887e7ff57330176265453bf8f17f55d2a7", kill_on_drop: false }`
[INFO] [stdout] ba2362e648f90edb03f73ce9d2eb55887e7ff57330176265453bf8f17f55d2a7