[INFO] fetching crate jn 0.1.0...
[INFO] documenting jn-0.1.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate jn 0.1.0 into /workspace/builds/worker-67/source
[INFO] validating manifest of crates.io crate jn 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] removed /workspace/builds/worker-67/source/rust-toolchain
[INFO] started tweaking crates.io crate jn 0.1.0
[INFO] finished tweaking crates.io crate jn 0.1.0
[INFO] tweaked toml for crates.io crate jn 0.1.0 written to /workspace/builds/worker-67/source/Cargo.toml
[INFO] crate crates.io crate jn 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/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] 74cba545a78936f5234c512ea25b6666deef29a7e4b02c9a69d9dc1d3c0a66ba
[INFO] running `Command { std: "docker" "start" "-a" "74cba545a78936f5234c512ea25b6666deef29a7e4b02c9a69d9dc1d3c0a66ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "74cba545a78936f5234c512ea25b6666deef29a7e4b02c9a69d9dc1d3c0a66ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "74cba545a78936f5234c512ea25b6666deef29a7e4b02c9a69d9dc1d3c0a66ba", kill_on_drop: false }`
[INFO] [stdout] 74cba545a78936f5234c512ea25b6666deef29a7e4b02c9a69d9dc1d3c0a66ba
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/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] 4b1f3a26ebb993b02c019bc09b71421e272ec3b9a8cd8277e04842e72087537b
[INFO] running `Command { std: "docker" "start" "-a" "4b1f3a26ebb993b02c019bc09b71421e272ec3b9a8cd8277e04842e72087537b", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling proc-macro2 v1.0.8
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling ryu v1.0.2
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]     Checking match_cfg v0.1.0
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking itoa v0.4.5
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking time v0.1.42
[INFO] [stderr]     Checking dirs-sys v0.3.4
[INFO] [stderr]     Checking hostname v0.3.0
[INFO] [stderr]     Checking dirs v2.0.2
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]     Checking serde_json v1.0.48
[INFO] [stderr]     Checking chrono v0.4.10
[INFO] [stderr]  Documenting jn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(map_first_last)]
[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 `jn`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name jn src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern chrono=/opt/rustwide/target/debug/deps/libchrono-dd82af323491d86e.rmeta --extern clap=/opt/rustwide/target/debug/deps/libclap-31c1aa2a0d7740ed.rmeta --extern dirs=/opt/rustwide/target/debug/deps/libdirs-849916e9cbd25b83.rmeta --extern hostname=/opt/rustwide/target/debug/deps/libhostname-0c0f8aa7341ea103.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-a521f12ed9e693b2.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-b8b26b938e0a87ce.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "4b1f3a26ebb993b02c019bc09b71421e272ec3b9a8cd8277e04842e72087537b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4b1f3a26ebb993b02c019bc09b71421e272ec3b9a8cd8277e04842e72087537b", kill_on_drop: false }`
[INFO] [stdout] 4b1f3a26ebb993b02c019bc09b71421e272ec3b9a8cd8277e04842e72087537b
