[INFO] fetching crate rusty-p4 0.1.0-alpha.2...
[INFO] testing rusty-p4-0.1.0-alpha.2 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate rusty-p4 0.1.0-alpha.2 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate rusty-p4 0.1.0-alpha.2 on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 38a14b746b46aa498f8345826470e747ef2fdba4c38ea1c7e8c13a33e2225ce3
[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" "38a14b746b46aa498f8345826470e747ef2fdba4c38ea1c7e8c13a33e2225ce3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "38a14b746b46aa498f8345826470e747ef2fdba4c38ea1c7e8c13a33e2225ce3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "38a14b746b46aa498f8345826470e747ef2fdba4c38ea1c7e8c13a33e2225ce3", kill_on_drop: false }`
[INFO] [stdout] 38a14b746b46aa498f8345826470e747ef2fdba4c38ea1c7e8c13a33e2225ce3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "RUSTFLAGS=--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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 96668ea04aee38fd74f81a8edbebbd30dde89cd86b3b366be284adbed80f6af3
[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" "96668ea04aee38fd74f81a8edbebbd30dde89cd86b3b366be284adbed80f6af3", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling pin-project-internal v0.4.0-alpha.11
[INFO] [stderr]    Compiling protobuf v2.25.1
[INFO] [stderr]    Compiling bindgen v0.51.1
[INFO] [stderr]    Compiling fixedbitset v0.2.0
[INFO] [stderr]    Compiling peeking_take_while v0.1.2
[INFO] [stderr]    Compiling multimap v0.8.3
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling tracing-core v0.1.19
[INFO] [stderr]    Compiling cmake v0.1.45
[INFO] [stderr]    Compiling clang-sys v0.28.1
[INFO] [stderr]    Compiling futures01 v0.1.31
[INFO] [stderr]    Compiling libz-sys v1.1.3
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling which v3.1.1
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling petgraph v0.5.1
[INFO] [stderr]    Compiling mio-uds v0.6.8
[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 futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling prost-build v0.6.1
[INFO] [stderr]    Compiling aho-corasick v0.7.18
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling object v0.26.2
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling cexpr v0.3.6
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta 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]   |                                      ^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[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 `futures-util-preview` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "96668ea04aee38fd74f81a8edbebbd30dde89cd86b3b366be284adbed80f6af3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "96668ea04aee38fd74f81a8edbebbd30dde89cd86b3b366be284adbed80f6af3", kill_on_drop: false }`
[INFO] [stdout] 96668ea04aee38fd74f81a8edbebbd30dde89cd86b3b366be284adbed80f6af3