[INFO] fetching crate marks 0.1.0...
[INFO] documenting marks-0.1.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate marks 0.1.0 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate marks 0.1.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate marks 0.1.0
[INFO] finished tweaking crates.io crate marks 0.1.0
[INFO] tweaked toml for crates.io crate marks 0.1.0 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate crates.io crate marks 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ad5a7e60a12b9a3bea49b47ffee871067bccb30f8c92c3fb89e5ac78853e1970
[INFO] running `Command { std: "docker" "start" "-a" "ad5a7e60a12b9a3bea49b47ffee871067bccb30f8c92c3fb89e5ac78853e1970", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ad5a7e60a12b9a3bea49b47ffee871067bccb30f8c92c3fb89e5ac78853e1970", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad5a7e60a12b9a3bea49b47ffee871067bccb30f8c92c3fb89e5ac78853e1970", kill_on_drop: false }`
[INFO] [stdout] ad5a7e60a12b9a3bea49b47ffee871067bccb30f8c92c3fb89e5ac78853e1970
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4a46538eb163e5d940f196b97d606c70ac955d6091b99f7e02e05f5069748648
[INFO] running `Command { std: "docker" "start" "-a" "4a46538eb163e5d940f196b97d606c70ac955d6091b99f7e02e05f5069748648", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.54
[INFO] [stderr]    Compiling const_fn v0.4.3
[INFO] [stderr]    Compiling memoffset v0.6.1
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking dirs-sys v0.3.5
[INFO] [stderr]     Checking fuzzy-matcher v0.3.7
[INFO] [stderr]     Checking crossbeam-channel v0.5.0
[INFO] [stderr]     Checking dirs v2.0.2
[INFO] [stderr]     Checking term v0.6.1
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking crossbeam-epoch v0.9.1
[INFO] [stderr]     Checking crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]     Checking rayon-core v1.9.0
[INFO] [stderr]     Checking rayon v1.5.0
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling paw-attributes v1.0.2
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]     Checking paw v1.0.0
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]  Documenting marks 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:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(iterator_fold_self)]
[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 `marks`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name marks src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern clap=/opt/rustwide/target/debug/deps/libclap-9eab12305f80c7ff.rmeta --extern fuzzy_matcher=/opt/rustwide/target/debug/deps/libfuzzy_matcher-e78f142fbdf231a6.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-acd7d23482fe8b54.rmeta --extern paw=/opt/rustwide/target/debug/deps/libpaw-be78a2e2d680981b.rmeta --extern rayon=/opt/rustwide/target/debug/deps/librayon-83a958caf7cd40d2.rmeta --extern regex=/opt/rustwide/target/debug/deps/libregex-9e8c984ff6f836bc.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-f431720d7f9bd0da.rmeta --extern term=/opt/rustwide/target/debug/deps/libterm-1cdaf23a623487e3.rmeta --extern walkdir=/opt/rustwide/target/debug/deps/libwalkdir-02dc6bfcfb89f9cc.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "4a46538eb163e5d940f196b97d606c70ac955d6091b99f7e02e05f5069748648", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a46538eb163e5d940f196b97d606c70ac955d6091b99f7e02e05f5069748648", kill_on_drop: false }`
[INFO] [stdout] 4a46538eb163e5d940f196b97d606c70ac955d6091b99f7e02e05f5069748648
