[INFO] fetching crate kf-protocol 3.0.0...
[INFO] documenting kf-protocol-3.0.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate kf-protocol 3.0.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate kf-protocol 3.0.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate kf-protocol 3.0.0
[INFO] finished tweaking crates.io crate kf-protocol 3.0.0
[INFO] tweaked toml for crates.io crate kf-protocol 3.0.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ed4761ab42386d16aed30e04d2f5d72c94c2cfe7a53058e9113f0406eeab18d2
[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" "ed4761ab42386d16aed30e04d2f5d72c94c2cfe7a53058e9113f0406eeab18d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ed4761ab42386d16aed30e04d2f5d72c94c2cfe7a53058e9113f0406eeab18d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ed4761ab42386d16aed30e04d2f5d72c94c2cfe7a53058e9113f0406eeab18d2", kill_on_drop: false }`
[INFO] [stdout] ed4761ab42386d16aed30e04d2f5d72c94c2cfe7a53058e9113f0406eeab18d2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ccabf33bcae28c7fe6d1f2d13826b380095168d7689397fb5c34980fe40d47b5
[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" "ccabf33bcae28c7fe6d1f2d13826b380095168d7689397fb5c34980fe40d47b5", kill_on_drop: false }`
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]     Checking futures-io v0.3.6
[INFO] [stderr]     Checking cache-padded v1.1.1
[INFO] [stderr]     Checking parking v2.0.0
[INFO] [stderr]     Checking fastrand v1.4.0
[INFO] [stderr]     Checking waker-fn v1.1.0
[INFO] [stderr]     Checking ansi_term v0.12.1
[INFO] [stderr]     Checking vec-arena v1.0.0
[INFO] [stderr]     Checking async-task v4.0.3
[INFO] [stderr]     Checking event-listener v2.5.1
[INFO] [stderr]     Checking atomic-waker v1.0.0
[INFO] [stderr]    Compiling crc32c v0.5.0
[INFO] [stderr]    Compiling nix v0.17.0
[INFO] [stderr]     Checking futures-timer v2.0.2
[INFO] [stderr]     Checking tracing-core v0.1.17
[INFO] [stderr]     Checking sharded-slab v0.0.9
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]     Checking regex v1.4.1
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stderr]     Checking concurrent-queue v1.2.2
[INFO] [stderr]     Checking byteorder v1.3.4
[INFO] [stderr]     Checking nb-connect v1.0.2
[INFO] [stderr]     Checking memmap v0.7.0
[INFO] [stderr]     Checking async-mutex v1.4.0
[INFO] [stderr]     Checking content_inspector v0.2.4
[INFO] [stderr]     Checking futures-lite v1.11.1
[INFO] [stderr]     Checking num-integer v0.1.43
[INFO] [stderr]     Checking async-channel v1.5.1
[INFO] [stderr]    Compiling num-derive v0.2.5
[INFO] [stderr]     Checking futures-util v0.3.6
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]     Checking tracing v0.1.21
[INFO] [stderr]     Checking tracing-serde v0.1.2
[INFO] [stderr]     Checking chrono v0.4.19
[INFO] [stderr]     Checking tracing-log v0.1.1
[INFO] [stderr]     Checking polling v2.0.2
[INFO] [stderr]     Checking kv-log-macro v1.0.7
[INFO] [stderr]    Compiling kf-protocol-derive v0.2.0
[INFO] [stderr]     Checking paste v0.1.18
[INFO] [stderr]     Checking async-io v1.1.10
[INFO] [stderr]     Checking async-executor v1.3.0
[INFO] [stderr]     Checking blocking v1.0.2
[INFO] [stderr]     Checking matchers v0.0.1
[INFO] [stderr]     Checking async-global-executor v1.4.0
[INFO] [stderr]     Checking async-std v1.6.5
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]     Checking tracing-subscriber v0.2.13
[INFO] [stderr]     Checking kf-protocol-core v0.1.2
[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/kf-protocol-core-0.1.2/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[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 `kf-protocol-core`.
[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" "ccabf33bcae28c7fe6d1f2d13826b380095168d7689397fb5c34980fe40d47b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ccabf33bcae28c7fe6d1f2d13826b380095168d7689397fb5c34980fe40d47b5", kill_on_drop: false }`
[INFO] [stdout] ccabf33bcae28c7fe6d1f2d13826b380095168d7689397fb5c34980fe40d47b5
