[INFO] fetching crate nibble 0.1.0...
[INFO] documenting nibble-0.1.0 against beta-2021-08-01 for beta-1.55-rustdoc-1
[INFO] extracting crate nibble 0.1.0 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate nibble 0.1.0 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nibble 0.1.0
[INFO] finished tweaking crates.io crate nibble 0.1.0
[INFO] tweaked toml for crates.io crate nibble 0.1.0 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "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" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] edceb1ba13ffb48d1c67ab125f80b846651b9862b26925463dcf463e029e4482
[INFO] running `Command { std: "docker" "start" "-a" "edceb1ba13ffb48d1c67ab125f80b846651b9862b26925463dcf463e029e4482", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "edceb1ba13ffb48d1c67ab125f80b846651b9862b26925463dcf463e029e4482", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "edceb1ba13ffb48d1c67ab125f80b846651b9862b26925463dcf463e029e4482", kill_on_drop: false }`
[INFO] [stdout] edceb1ba13ffb48d1c67ab125f80b846651b9862b26925463dcf463e029e4482
[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" "+beta-2021-08-01" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fb86f525d4e4e52e111cf48a4dfc61c179c7cacdf542136cbdf34cfae02518d4
[INFO] running `Command { std: "docker" "start" "-a" "fb86f525d4e4e52e111cf48a4dfc61c179c7cacdf542136cbdf34cfae02518d4", 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] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]  Documenting nibble v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(try_from)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(trace_macros)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 `nibble`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name nibble src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="std"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern arrayvec=/opt/rustwide/target/debug/deps/libarrayvec-ddd04eb4938ba731.rmeta --extern cfg_if=/opt/rustwide/target/debug/deps/libcfg_if-949b7287e2e92eea.rmeta --extern num_traits=/opt/rustwide/target/debug/deps/libnum_traits-a0d1b10ff0223a83.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "fb86f525d4e4e52e111cf48a4dfc61c179c7cacdf542136cbdf34cfae02518d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb86f525d4e4e52e111cf48a4dfc61c179c7cacdf542136cbdf34cfae02518d4", kill_on_drop: false }`
[INFO] [stdout] fb86f525d4e4e52e111cf48a4dfc61c179c7cacdf542136cbdf34cfae02518d4
