[INFO] fetching crate rusty-p4 0.1.0-alpha.2...
[INFO] documenting rusty-p4-0.1.0-alpha.2 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate rusty-p4 0.1.0-alpha.2 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate rusty-p4 0.1.0-alpha.2 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 rusty-p4 0.1.0-alpha.2
[INFO] finished tweaking crates.io crate rusty-p4 0.1.0-alpha.2
[INFO] tweaked toml for crates.io crate rusty-p4 0.1.0-alpha.2 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 815439f4a6c9550dce33c4a0e01f6323ae6e4edc5f683ebd85c7a8e82950bd94
[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" "815439f4a6c9550dce33c4a0e01f6323ae6e4edc5f683ebd85c7a8e82950bd94", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "815439f4a6c9550dce33c4a0e01f6323ae6e4edc5f683ebd85c7a8e82950bd94", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "815439f4a6c9550dce33c4a0e01f6323ae6e4edc5f683ebd85c7a8e82950bd94", kill_on_drop: false }`
[INFO] [stdout] 815439f4a6c9550dce33c4a0e01f6323ae6e4edc5f683ebd85c7a8e82950bd94
[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" "+1.46.0" "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] 786a7e4740249d3ab34669ee08842201e17e3eed6dd8eb93c49f6e5ec30d6b30
[INFO] running `Command { std: "docker" "start" "-a" "786a7e4740249d3ab34669ee08842201e17e3eed6dd8eb93c49f6e5ec30d6b30", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling either v1.6.0
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling glob v0.3.0
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling protobuf v2.17.0
[INFO] [stderr]    Compiling pin-project-internal v0.4.0-alpha.11
[INFO] [stderr]    Compiling adler v0.2.3
[INFO] [stderr]    Compiling bindgen v0.51.1
[INFO] [stderr]    Compiling gimli v0.22.0
[INFO] [stderr]    Compiling rustc-hash v1.1.0
[INFO] [stderr]    Compiling same-file v1.0.6
[INFO] [stderr]    Compiling shlex v0.1.1
[INFO] [stderr]    Compiling rustc-demangle v0.1.16
[INFO] [stderr]    Compiling peeking_take_while v0.1.2
[INFO] [stderr]    Compiling object v0.20.0
[INFO] [stderr]    Compiling lexical-core v0.7.4
[INFO] [stderr]     Checking arrayvec v0.5.1
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling cmake v0.1.44
[INFO] [stderr]     Checking tracing-core v0.1.15
[INFO] [stderr]     Checking futures01 v0.1.29
[INFO] [stderr]    Compiling libz-sys v1.1.1
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling walkdir v2.3.1
[INFO] [stderr]    Compiling miniz_oxide v0.4.1
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling hashbrown v0.8.2
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]    Compiling clang-sys v0.28.1
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling indexmap v1.5.2
[INFO] [stderr]    Compiling cexpr v0.3.6
[INFO] [stderr]    Compiling petgraph v0.5.1
[INFO] [stderr]    Compiling tempfile v3.1.0
[INFO] [stderr]    Compiling addr2line v0.13.0
[INFO] [stderr]    Compiling backtrace v0.3.50
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling prost-derive v0.6.1
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling tracing-attributes v0.1.11
[INFO] [stderr]    Compiling derive-new v0.5.8
[INFO] [stderr]    Compiling tokio-macros v0.2.0-alpha.5
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling failure v0.1.8
[INFO] [stderr]    Compiling prost-derive v0.5.0
[INFO] [stderr]     Checking pin-project v0.4.0-alpha.11
[INFO] [stderr]     Checking tokio-io v0.2.0-alpha.5
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling grpcio-sys v0.5.4
[INFO] [stderr]     Checking tracing v0.1.19
[INFO] [stderr]     Checking tokio-codec v0.2.0-alpha.5
[INFO] [stderr]    Compiling prost v0.6.1
[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/futures-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling prost-types v0.6.1
[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 `futures-util-preview`.
[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" "786a7e4740249d3ab34669ee08842201e17e3eed6dd8eb93c49f6e5ec30d6b30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "786a7e4740249d3ab34669ee08842201e17e3eed6dd8eb93c49f6e5ec30d6b30", kill_on_drop: false }`
[INFO] [stdout] 786a7e4740249d3ab34669ee08842201e17e3eed6dd8eb93c49f6e5ec30d6b30