[INFO] fetching crate variadic_monoids 0.1.1...
[INFO] documenting variadic_monoids-0.1.1 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate variadic_monoids 0.1.1 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate variadic_monoids 0.1.1 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 variadic_monoids 0.1.1
[INFO] finished tweaking crates.io crate variadic_monoids 0.1.1
[INFO] tweaked toml for crates.io crate variadic_monoids 0.1.1 written to /workspace/builds/worker-12/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]  Downloading crates ...
[INFO] [stderr]   Downloaded tuple_list v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] b40f418ce0c2a68dec11ff5a15657fe0bdf1ef28de0be074f912eba8a9f3cc87
[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" "b40f418ce0c2a68dec11ff5a15657fe0bdf1ef28de0be074f912eba8a9f3cc87", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b40f418ce0c2a68dec11ff5a15657fe0bdf1ef28de0be074f912eba8a9f3cc87", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b40f418ce0c2a68dec11ff5a15657fe0bdf1ef28de0be074f912eba8a9f3cc87", kill_on_drop: false }`
[INFO] [stdout] b40f418ce0c2a68dec11ff5a15657fe0bdf1ef28de0be074f912eba8a9f3cc87
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 5c2769c4b63c9a4bec2be7acb173375c1cb5bc1b9f69fd0878c34ccb5fb3b94a
[INFO] running `Command { std: "docker" "start" "-a" "5c2769c4b63c9a4bec2be7acb173375c1cb5bc1b9f69fd0878c34ccb5fb3b94a", kill_on_drop: false }`
[INFO] [stderr]     Checking tuple_list v0.1.2
[INFO] [stderr]  Documenting variadic_monoids v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(fn_traits, unboxed_closures)]
[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:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(const_fn)]
[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:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(const_generics)]
[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:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(unsized_locals)]
[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:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(trivial_bounds)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 6 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 `variadic_monoids`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name variadic_monoids 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 tuple_list=/opt/rustwide/target/debug/deps/libtuple_list-723e765cce046489.rmeta --cap-lints=warn --crate-version 0.1.1` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "5c2769c4b63c9a4bec2be7acb173375c1cb5bc1b9f69fd0878c34ccb5fb3b94a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5c2769c4b63c9a4bec2be7acb173375c1cb5bc1b9f69fd0878c34ccb5fb3b94a", kill_on_drop: false }`
[INFO] [stdout] 5c2769c4b63c9a4bec2be7acb173375c1cb5bc1b9f69fd0878c34ccb5fb3b94a