[INFO] cloning repository https://github.com/KerrMetric/virtue
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/KerrMetric/virtue" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FKerrMetric%2Fvirtue", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FKerrMetric%2Fvirtue'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ace5e07cabfea2cf22f43e6e7c984e77ac9a8443
[INFO] testing KerrMetric/virtue against 1.59.0 for beta-1.60-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FKerrMetric%2Fvirtue" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/KerrMetric/virtue on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-8/source/.cargo/config
[INFO] started tweaking git repo https://github.com/KerrMetric/virtue
[INFO] finished tweaking git repo https://github.com/KerrMetric/virtue
[INFO] tweaked toml for git repo https://github.com/KerrMetric/virtue written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/KerrMetric/virtue already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded toml v0.5.3
[INFO] [stderr]   Downloaded byte-slice-cast v0.3.2
[INFO] [stderr]   Downloaded bitvec v0.14.0
[INFO] [stderr]   Downloaded parity-scale-codec-derive v1.0.3
[INFO] [stderr]   Downloaded parity-scale-codec v1.0.6
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 902c3e6897a7063b95211731c5530efc8db89127c96eef11fadf97091d8cfb69
[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" "902c3e6897a7063b95211731c5530efc8db89127c96eef11fadf97091d8cfb69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "902c3e6897a7063b95211731c5530efc8db89127c96eef11fadf97091d8cfb69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "902c3e6897a7063b95211731c5530efc8db89127c96eef11fadf97091d8cfb69", kill_on_drop: false }`
[INFO] [stdout] 902c3e6897a7063b95211731c5530efc8db89127c96eef11fadf97091d8cfb69
[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" "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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e1fd841c1ed206107f87603be0d97d37cb3230b7ffe84cb5a8f1438d81964573
[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" "e1fd841c1ed206107f87603be0d97d37cb3230b7ffe84cb5a8f1438d81964573", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.5
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling serde v1.0.101
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling wee_alloc v0.4.5
[INFO] [stderr]    Compiling arrayvec v0.4.11
[INFO] [stderr]    Compiling memory_units v0.4.0
[INFO] [stderr]    Compiling byte-slice-cast v0.3.2
[INFO] [stderr]    Compiling bitvec v0.14.0
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]    Compiling either v1.5.3
[INFO] [stderr]    Compiling ryu v1.0.0
[INFO] [stderr]    Compiling tiny-keccak v1.5.0
[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/smallvec-0.6.10/lib.rs:33:32
[INFO] [stdout]    |
[INFO] [stdout] 33 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[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 `smallvec` 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" "e1fd841c1ed206107f87603be0d97d37cb3230b7ffe84cb5a8f1438d81964573", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e1fd841c1ed206107f87603be0d97d37cb3230b7ffe84cb5a8f1438d81964573", kill_on_drop: false }`
[INFO] [stdout] e1fd841c1ed206107f87603be0d97d37cb3230b7ffe84cb5a8f1438d81964573