[INFO] fetching crate kunai 0.4.0...
[INFO] documenting kunai-0.4.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate kunai 0.4.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate kunai 0.4.0 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate kunai 0.4.0
[INFO] finished tweaking crates.io crate kunai 0.4.0
[INFO] tweaked toml for crates.io crate kunai 0.4.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate kunai 0.4.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d6441bade165d69f534f3c660cbbc3cbae1b7217e274b71f89ecefebb9d5947a
[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" "d6441bade165d69f534f3c660cbbc3cbae1b7217e274b71f89ecefebb9d5947a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d6441bade165d69f534f3c660cbbc3cbae1b7217e274b71f89ecefebb9d5947a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d6441bade165d69f534f3c660cbbc3cbae1b7217e274b71f89ecefebb9d5947a", kill_on_drop: false }`
[INFO] [stdout] d6441bade165d69f534f3c660cbbc3cbae1b7217e274b71f89ecefebb9d5947a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d81b63f8f721a29c704e303a76f45c84a6b3dba5ef11cd05a229eee2028ebdfd
[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" "d81b63f8f721a29c704e303a76f45c84a6b3dba5ef11cd05a229eee2028ebdfd", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.11
[INFO] [stderr]     Checking either v1.5.3
[INFO] [stderr]     Checking smallvec v1.1.0
[INFO] [stderr]    Compiling rustc-rayon-core v0.3.0
[INFO] [stderr]    Compiling string_cache_shared v0.3.0
[INFO] [stderr]    Compiling failure_derive v0.1.6
[INFO] [stderr]     Checking rustc-ap-graphviz v610.0.0
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling openssl v0.10.26
[INFO] [stderr]    Compiling itoa v0.4.4
[INFO] [stderr]     Checking new_debug_unreachable v1.0.3
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]     Checking precomputed-hash v0.1.1
[INFO] [stderr]    Compiling curl v0.4.25
[INFO] [stderr]    Compiling typenum v1.11.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-ap-graphviz-610.0.0/lib.rs:277:1
[INFO] [stdout]     |
[INFO] [stdout] 277 | #![feature(rustc_private, nll)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rustc-ap-graphviz`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "d81b63f8f721a29c704e303a76f45c84a6b3dba5ef11cd05a229eee2028ebdfd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d81b63f8f721a29c704e303a76f45c84a6b3dba5ef11cd05a229eee2028ebdfd", kill_on_drop: false }`
[INFO] [stdout] d81b63f8f721a29c704e303a76f45c84a6b3dba5ef11cd05a229eee2028ebdfd