[INFO] fetching crate scan-fonts 1.0.0...
[INFO] documenting scan-fonts-1.0.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate scan-fonts 1.0.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate scan-fonts 1.0.0 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 scan-fonts 1.0.0
[INFO] finished tweaking crates.io crate scan-fonts 1.0.0
[INFO] tweaked toml for crates.io crate scan-fonts 1.0.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4438a3b4b21e86c1cc7bd530f7b7aff999e89b43726c50d5cb25e12c423c7140
[INFO] running `Command { std: "docker" "start" "-a" "4438a3b4b21e86c1cc7bd530f7b7aff999e89b43726c50d5cb25e12c423c7140", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4438a3b4b21e86c1cc7bd530f7b7aff999e89b43726c50d5cb25e12c423c7140", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4438a3b4b21e86c1cc7bd530f7b7aff999e89b43726c50d5cb25e12c423c7140", kill_on_drop: false }`
[INFO] [stdout] 4438a3b4b21e86c1cc7bd530f7b7aff999e89b43726c50d5cb25e12c423c7140
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a87ff5e8f3e5376265d79d3fd3c87baa6cbe7d4bd8b62a09ca8ec59e60bb6c7a
[INFO] running `Command { std: "docker" "start" "-a" "a87ff5e8f3e5376265d79d3fd3c87baa6cbe7d4bd8b62a09ca8ec59e60bb6c7a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.3.8
[INFO] [stderr]     Checking backtrace v0.3.61
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]    Compiling syn v0.13.11
[INFO] [stderr]    Compiling getset v0.0.6
[INFO] [stderr]  Documenting scan-fonts v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable 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: 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 `scan-fonts`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name scan_fonts 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 failure=/opt/rustwide/target/debug/deps/libfailure-0e186ca75e8dc660.rmeta --extern getset=/opt/rustwide/target/debug/deps/libgetset-391a156158e04599.so --cap-lints=warn --crate-version 1.0.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "a87ff5e8f3e5376265d79d3fd3c87baa6cbe7d4bd8b62a09ca8ec59e60bb6c7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a87ff5e8f3e5376265d79d3fd3c87baa6cbe7d4bd8b62a09ca8ec59e60bb6c7a", kill_on_drop: false }`
[INFO] [stdout] a87ff5e8f3e5376265d79d3fd3c87baa6cbe7d4bd8b62a09ca8ec59e60bb6c7a
