[INFO] fetching crate alloc-cortex-m 0.4.1...
[INFO] testing alloc-cortex-m-0.4.1 against 1.54.0 for beta-1.55-1
[INFO] extracting crate alloc-cortex-m 0.4.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate alloc-cortex-m 0.4.1 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate alloc-cortex-m 0.4.1
[INFO] finished tweaking crates.io crate alloc-cortex-m 0.4.1
[INFO] tweaked toml for crates.io crate alloc-cortex-m 0.4.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate alloc-cortex-m 0.4.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--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-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "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] a237f38ac7c4d264a5978ca37dd61541b88704b0672587815e2129cfd972f98d
[INFO] running `Command { std: "docker" "start" "-a" "a237f38ac7c4d264a5978ca37dd61541b88704b0672587815e2129cfd972f98d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a237f38ac7c4d264a5978ca37dd61541b88704b0672587815e2129cfd972f98d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a237f38ac7c4d264a5978ca37dd61541b88704b0672587815e2129cfd972f98d", kill_on_drop: false }`
[INFO] [stdout] a237f38ac7c4d264a5978ca37dd61541b88704b0672587815e2129cfd972f98d
[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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--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] 7746ec7e9be377809804b7116d79364f0dd020054f8b36b6a4b7709a43b7c46d
[INFO] running `Command { std: "docker" "start" "-a" "7746ec7e9be377809804b7116d79364f0dd020054f8b36b6a4b7709a43b7c46d", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling cortex-m v0.6.4
[INFO] [stderr]    Compiling linked_list_allocator v0.8.11
[INFO] [stderr]    Compiling generic-array v0.14.4
[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/linked_list_allocator-0.8.11/src/lib.rs:1:41
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(feature = "const_mut_refs", feature(const_mut_refs))]
[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 `linked_list_allocator`
[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" "7746ec7e9be377809804b7116d79364f0dd020054f8b36b6a4b7709a43b7c46d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7746ec7e9be377809804b7116d79364f0dd020054f8b36b6a4b7709a43b7c46d", kill_on_drop: false }`
[INFO] [stdout] 7746ec7e9be377809804b7116d79364f0dd020054f8b36b6a4b7709a43b7c46d
