[INFO] fetching crate loader-rs 0.7.0...
[INFO] documenting loader-rs-0.7.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate loader-rs 0.7.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate loader-rs 0.7.0 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate loader-rs 0.7.0
[INFO] finished tweaking crates.io crate loader-rs 0.7.0
[INFO] tweaked toml for crates.io crate loader-rs 0.7.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded cached_proc_macro v0.3.0
[INFO] [stderr]   Downloaded json-trait-rs v0.11.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 56a1d6e42f80ae7989ff50e4448f32971068cc85d459a8dc57c3b0ddc7a3e831
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "56a1d6e42f80ae7989ff50e4448f32971068cc85d459a8dc57c3b0ddc7a3e831", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "56a1d6e42f80ae7989ff50e4448f32971068cc85d459a8dc57c3b0ddc7a3e831", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56a1d6e42f80ae7989ff50e4448f32971068cc85d459a8dc57c3b0ddc7a3e831", kill_on_drop: false }`
[INFO] [stdout] 56a1d6e42f80ae7989ff50e4448f32971068cc85d459a8dc57c3b0ddc7a3e831
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dc141aebfa1ca01d357fa807482aaabfc4c4cbbf2a0307c4201825d482f73df0
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "dc141aebfa1ca01d357fa807482aaabfc4c4cbbf2a0307c4201825d482f73df0", kill_on_drop: false }`
[INFO] [stderr]    Compiling strsim v0.9.3
[INFO] [stderr]    Compiling event-listener v2.4.0
[INFO] [stderr]     Checking strum v0.19.2
[INFO] [stderr]     Checking serde_urlencoded v0.6.1
[INFO] [stderr]    Compiling strum_macros v0.19.2
[INFO] [stderr]     Checking async-compression v0.3.5
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stderr]     Checking futures-util v0.3.5
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling async-mutex v1.2.0
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]     Checking tokio-tls v0.3.1
[INFO] [stderr]     Checking h2 v0.2.6
[INFO] [stderr]    Compiling darling v0.10.2
[INFO] [stderr]    Compiling cached_proc_macro v0.3.0
[INFO] [stderr]     Checking cached v0.18.0
[INFO] [stderr]     Checking hyper v0.13.7
[INFO] [stderr]     Checking hyper-tls v0.4.3
[INFO] [stderr]     Checking reqwest v0.10.8
[INFO] [stderr]  Documenting loader-rs v0.7.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:43:1
[INFO] [stdout]    |
[INFO] [stdout] 43 | #![feature(specialization)]
[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 `loader-rs`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name loader_rs src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern cached=/opt/rustwide/target/debug/deps/libcached-e49824cd84270950.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-db88f49d9e5662e7.rmeta --extern parking_lot=/opt/rustwide/target/debug/deps/libparking_lot-9971c8e565151e74.rmeta --extern reqwest=/opt/rustwide/target/debug/deps/libreqwest-61fde4570a04be4e.rmeta --extern strum=/opt/rustwide/target/debug/deps/libstrum-a598e74983bdba8d.rmeta --extern strum_macros=/opt/rustwide/target/debug/deps/libstrum_macros-bfda92770f237670.so --extern url=/opt/rustwide/target/debug/deps/liburl-ead0c533f54ff04b.rmeta --cap-lints=warn --crate-version 0.7.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "dc141aebfa1ca01d357fa807482aaabfc4c4cbbf2a0307c4201825d482f73df0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dc141aebfa1ca01d357fa807482aaabfc4c4cbbf2a0307c4201825d482f73df0", kill_on_drop: false }`
[INFO] [stdout] dc141aebfa1ca01d357fa807482aaabfc4c4cbbf2a0307c4201825d482f73df0