[INFO] crate arrav 0.2.0 is already in cache
[INFO] testing arrav-0.2.0 against 1.45.2 for beta-1.46-1
[INFO] extracting crate arrav 0.2.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate arrav 0.2.0 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate arrav 0.2.0
[INFO] finished tweaking crates.io crate arrav 0.2.0
[INFO] tweaked toml for crates.io crate arrav 0.2.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", 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] ee7fe3732d7c3e06299301ee714c1a073f16fda32091b4a9e47f2b7e668b7ea1
[INFO] running `Command { std: "docker" "start" "-a" "ee7fe3732d7c3e06299301ee714c1a073f16fda32091b4a9e47f2b7e668b7ea1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ee7fe3732d7c3e06299301ee714c1a073f16fda32091b4a9e47f2b7e668b7ea1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ee7fe3732d7c3e06299301ee714c1a073f16fda32091b4a9e47f2b7e668b7ea1", kill_on_drop: false }`
[INFO] [stdout] ee7fe3732d7c3e06299301ee714c1a073f16fda32091b4a9e47f2b7e668b7ea1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7495bf5694b29e053c5d8e05a03636a99f329b21e543bce5bedc0dbe8cfd9be0
[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" "7495bf5694b29e053c5d8e05a03636a99f329b21e543bce5bedc0dbe8cfd9be0", kill_on_drop: false }`
[INFO] [stderr]    Compiling arrav v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:91:1
[INFO] [stdout]    |
[INFO] [stdout] 91 | / #![feature(
[INFO] [stdout] 92 | |     const_generics,
[INFO] [stdout] 93 | |     const_generic_impls_guard,
[INFO] [stdout] 94 | |     const_fn,
[INFO] [stdout] ...  |
[INFO] [stdout] 97 | |     slice_index_methods
[INFO] [stdout] 98 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:99:41
[INFO] [stdout]    |
[INFO] [stdout] 99 | #![cfg_attr(feature = "specialization", feature(min_specialization))]
[INFO] [stdout]    |                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `arrav`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "7495bf5694b29e053c5d8e05a03636a99f329b21e543bce5bedc0dbe8cfd9be0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7495bf5694b29e053c5d8e05a03636a99f329b21e543bce5bedc0dbe8cfd9be0", kill_on_drop: false }`
[INFO] [stdout] 7495bf5694b29e053c5d8e05a03636a99f329b21e543bce5bedc0dbe8cfd9be0