[INFO] fetching crate commune 0.0.2...
[INFO] testing commune-0.0.2 against 1.49.0 for beta-1.50-1
[INFO] extracting crate commune 0.0.2 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate commune 0.0.2 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate commune 0.0.2
[INFO] finished tweaking crates.io crate commune 0.0.2
[INFO] tweaked toml for crates.io crate commune 0.0.2 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6128a4a667fa6c7de80d0097a3deb7033b28a8b3132078091b3a4242e960087b
[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" "6128a4a667fa6c7de80d0097a3deb7033b28a8b3132078091b3a4242e960087b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6128a4a667fa6c7de80d0097a3deb7033b28a8b3132078091b3a4242e960087b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6128a4a667fa6c7de80d0097a3deb7033b28a8b3132078091b3a4242e960087b", kill_on_drop: false }`
[INFO] [stdout] 6128a4a667fa6c7de80d0097a3deb7033b28a8b3132078091b3a4242e960087b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cc2bf009944885ef0720ae5b3b025ed4f0b220d2293ea6488474ef2c87bac740
[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" "cc2bf009944885ef0720ae5b3b025ed4f0b220d2293ea6488474ef2c87bac740", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling cortex-m v0.6.4
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling heapless v0.5.6
[INFO] [stderr]    Compiling cortex-m-rt v0.6.13
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling r0 v0.2.2
[INFO] [stderr]    Compiling rtic-core v0.3.1
[INFO] [stderr]    Compiling arrayvec v0.5.2
[INFO] [stderr]    Compiling cortex-m-rtic v0.5.5
[INFO] [stderr]    Compiling generic-array v0.13.2
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling volatile-register v0.2.0
[INFO] [stderr]    Compiling as-slice v0.1.4
[INFO] [stderr]    Compiling aligned v0.3.4
[INFO] [stderr]    Compiling rtic-syntax v0.4.0
[INFO] [stderr]    Compiling cortex-m-rt-macros v0.1.8
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]    Compiling cortex-m-rtic-macros v0.5.2
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling serde_cbor v0.11.1
[INFO] [stderr]    Compiling commune v0.0.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(const_in_array_repeat_expressions)]
[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:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(const_fn)]
[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 `commune`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "cc2bf009944885ef0720ae5b3b025ed4f0b220d2293ea6488474ef2c87bac740", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cc2bf009944885ef0720ae5b3b025ed4f0b220d2293ea6488474ef2c87bac740", kill_on_drop: false }`
[INFO] [stdout] cc2bf009944885ef0720ae5b3b025ed4f0b220d2293ea6488474ef2c87bac740