[INFO] fetching crate fct 0.1.1...
[INFO] documenting fct-0.1.1 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate fct 0.1.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate fct 0.1.1 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 fct 0.1.1
[INFO] finished tweaking crates.io crate fct 0.1.1
[INFO] tweaked toml for crates.io crate fct 0.1.1 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate crates.io crate fct 0.1.1 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] [stderr]     Blocking waiting for file lock on package cache
[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" "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] e593680f0aaf1f4609c912727feae46978da80cac008cfd0f9d685f6943e53b7
[INFO] running `Command { std: "docker" "start" "-a" "e593680f0aaf1f4609c912727feae46978da80cac008cfd0f9d685f6943e53b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e593680f0aaf1f4609c912727feae46978da80cac008cfd0f9d685f6943e53b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e593680f0aaf1f4609c912727feae46978da80cac008cfd0f9d685f6943e53b7", kill_on_drop: false }`
[INFO] [stdout] e593680f0aaf1f4609c912727feae46978da80cac008cfd0f9d685f6943e53b7
[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" "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] 4117fa3f27aee3e7b427001f88a8ebf00520e98824940482a10ad386d9f4e00b
[INFO] running `Command { std: "docker" "start" "-a" "4117fa3f27aee3e7b427001f88a8ebf00520e98824940482a10ad386d9f4e00b", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]    Compiling proc-macro2 v1.0.12
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.19
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling version_check v0.9.1
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]    Compiling regex-syntax v0.6.20
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling siphasher v0.3.3
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling opaque-debug v0.2.3
[INFO] [stderr]    Compiling strsim v0.9.3
[INFO] [stderr]    Compiling fixedbitset v0.2.0
[INFO] [stderr]    Compiling new_debug_unreachable v1.0.4
[INFO] [stderr]    Compiling either v1.5.3
[INFO] [stderr]    Compiling precomputed-hash v0.1.1
[INFO] [stderr]    Compiling bit-vec v0.6.2
[INFO] [stderr]    Compiling fake-simd v0.1.2
[INFO] [stderr]    Compiling unicode-segmentation v1.6.0
[INFO] [stderr]    Compiling diff v0.1.12
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]    Compiling num-bigint v0.3.0
[INFO] [stderr]    Compiling num-rational v0.3.0
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling thread_local v1.0.1
[INFO] [stderr]    Compiling block-padding v0.1.5
[INFO] [stderr]    Compiling phf_shared v0.8.0
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling itertools v0.9.0
[INFO] [stderr]    Compiling bit-set v0.5.2
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling ena v0.14.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.2
[INFO] [stderr]    Compiling proc-macro-error v1.0.2
[INFO] [stderr]     Checking aho-corasick v0.7.10
[INFO] [stderr]    Compiling quote v1.0.4
[INFO] [stderr]    Compiling petgraph v0.5.1
[INFO] [stderr]    Compiling dirs v1.0.5
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling term v0.5.2
[INFO] [stderr]     Checking dirs-sys v0.3.5
[INFO] [stderr]    Compiling ascii-canvas v2.0.0
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking num-complex v0.3.0
[INFO] [stderr]     Checking dirs v2.0.2
[INFO] [stderr]     Checking dirs v3.0.1
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]     Checking term v0.6.1
[INFO] [stderr]    Compiling sha2 v0.8.1
[INFO] [stderr]    Compiling regex v1.4.1
[INFO] [stderr]    Compiling lalrpop-util v0.19.1
[INFO] [stderr]     Checking num v0.3.0
[INFO] [stderr]     Checking big-rational-str v0.1.3
[INFO] [stderr]    Compiling syn-mid v0.5.0
[INFO] [stderr]    Compiling serde_derive v1.0.106
[INFO] [stderr]    Compiling structopt-derive v0.4.7
[INFO] [stderr]     Checking structopt v0.3.14
[INFO] [stderr]    Compiling string_cache v0.8.0
[INFO] [stderr]    Compiling docopt v1.1.0
[INFO] [stderr]    Compiling lalrpop v0.19.1
[INFO] [stderr]    Compiling fct v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting fct v0.1.1 (/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(drain_filter)]
[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 `fct`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name fct 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 atty=/opt/rustwide/target/debug/deps/libatty-28dfb091aa5c5ab4.rmeta --extern big_rational_str=/opt/rustwide/target/debug/deps/libbig_rational_str-599ed300302e9548.rmeta --extern dirs=/opt/rustwide/target/debug/deps/libdirs-4d56825fd474eff6.rmeta --extern lalrpop_util=/opt/rustwide/target/debug/deps/liblalrpop_util-4af2e70774080681.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-acd7d23482fe8b54.rmeta --extern num=/opt/rustwide/target/debug/deps/libnum-11bd0abae06a178e.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-a3394e5c9e81fbad.rmeta --extern term=/opt/rustwide/target/debug/deps/libterm-f18611c4d6e25117.rmeta --cap-lints=warn --crate-version 0.1.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "4117fa3f27aee3e7b427001f88a8ebf00520e98824940482a10ad386d9f4e00b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4117fa3f27aee3e7b427001f88a8ebf00520e98824940482a10ad386d9f4e00b", kill_on_drop: false }`
[INFO] [stdout] 4117fa3f27aee3e7b427001f88a8ebf00520e98824940482a10ad386d9f4e00b
