[INFO] fetching crate driverkit 0.8.0...
[INFO] documenting driverkit-0.8.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate driverkit 0.8.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate driverkit 0.8.0 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 driverkit 0.8.0
[INFO] finished tweaking crates.io crate driverkit 0.8.0
[INFO] tweaked toml for crates.io crate driverkit 0.8.0 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate crates.io crate driverkit 0.8.0 already has a lockfile, it will not be regenerated
[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-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" "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] [stdout] ab34244986de1cb33fa439c97ab8dcee9dae34666079bc65f24fa780f0e7119b
[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" "ab34244986de1cb33fa439c97ab8dcee9dae34666079bc65f24fa780f0e7119b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ab34244986de1cb33fa439c97ab8dcee9dae34666079bc65f24fa780f0e7119b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab34244986de1cb33fa439c97ab8dcee9dae34666079bc65f24fa780f0e7119b", kill_on_drop: false }`
[INFO] [stdout] ab34244986de1cb33fa439c97ab8dcee9dae34666079bc65f24fa780f0e7119b
[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" "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] [stdout] 696e34be55f2320a7ca26274aad7bc1c1be73d379a3c7042a5f958d36280f79c
[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" "696e34be55f2320a7ca26274aad7bc1c1be73d379a3c7042a5f958d36280f79c", kill_on_drop: false }`
[INFO] [stderr]    Compiling x86 v0.40.0
[INFO] [stderr]     Checking bit_field v0.10.1
[INFO] [stderr]     Checking custom_error v1.9.2
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking raw-cpuid v9.0.0
[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/custom_error-1.9.2/src/lib.rs:3:35
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![cfg_attr(feature = "unstable", feature(allocator_api, try_reserve))]
[INFO] [stdout]   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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 `custom_error`
[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" "696e34be55f2320a7ca26274aad7bc1c1be73d379a3c7042a5f958d36280f79c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "696e34be55f2320a7ca26274aad7bc1c1be73d379a3c7042a5f958d36280f79c", kill_on_drop: false }`
[INFO] [stdout] 696e34be55f2320a7ca26274aad7bc1c1be73d379a3c7042a5f958d36280f79c
