[INFO] fetching crate frcds 0.1.0...
[INFO] documenting frcds-0.1.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate frcds 0.1.0 into /workspace/builds/worker-112/source
[INFO] validating manifest of crates.io crate frcds 0.1.0 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 frcds 0.1.0
[INFO] finished tweaking crates.io crate frcds 0.1.0
[INFO] tweaked toml for crates.io crate frcds 0.1.0 written to /workspace/builds/worker-112/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "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" "+1.61.0" "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-112/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/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] [stdout] 2b855a182a607d0e3378128ee438f53c680154b902d7c676516df82064d2ba63
[INFO] running `Command { std: "docker" "start" "-a" "2b855a182a607d0e3378128ee438f53c680154b902d7c676516df82064d2ba63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2b855a182a607d0e3378128ee438f53c680154b902d7c676516df82064d2ba63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2b855a182a607d0e3378128ee438f53c680154b902d7c676516df82064d2ba63", kill_on_drop: false }`
[INFO] [stdout] 2b855a182a607d0e3378128ee438f53c680154b902d7c676516df82064d2ba63
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/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] [stdout] e2e582b6f3381eacb6dc18a95b97953a27bc662802ebd5d3d616c14b48f9779a
[INFO] running `Command { std: "docker" "start" "-a" "e2e582b6f3381eacb6dc18a95b97953a27bc662802ebd5d3d616c14b48f9779a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling unicode-ident v1.0.0
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]     Checking adler v1.0.2
[INFO] [stderr]     Checking gimli v0.26.1
[INFO] [stderr]    Compiling unicode-xid v0.2.3
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking rustc-demangle v0.1.21
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]    Compiling backtrace v0.3.65
[INFO] [stderr]     Checking miniz_oxide v0.5.1
[INFO] [stderr]     Checking object v0.28.4
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking addr2line v0.17.0
[INFO] [stderr]    Compiling synstructure v0.12.6
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]  Documenting frcds v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: could not document `frcds`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name frcds src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=f065eb3e07324745 -L dependency=/opt/rustwide/target/debug/deps --extern bitflags=/opt/rustwide/target/debug/deps/libbitflags-22d7f70832a3b85e.rmeta --extern byteorder=/opt/rustwide/target/debug/deps/libbyteorder-7c274f399d426ec2.rmeta --extern failure=/opt/rustwide/target/debug/deps/libfailure-c88cfe258b39ebbc.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[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(nll)]
[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] running `Command { std: "docker" "inspect" "e2e582b6f3381eacb6dc18a95b97953a27bc662802ebd5d3d616c14b48f9779a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2e582b6f3381eacb6dc18a95b97953a27bc662802ebd5d3d616c14b48f9779a", kill_on_drop: false }`
[INFO] [stdout] e2e582b6f3381eacb6dc18a95b97953a27bc662802ebd5d3d616c14b48f9779a