[INFO] fetching crate ross-firmware 0.1.4...
[INFO] testing ross-firmware-0.1.4 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate ross-firmware 0.1.4 into /workspace/builds/worker-57/source
[INFO] validating manifest of crates.io crate ross-firmware 0.1.4 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] removed /workspace/builds/worker-57/source/.cargo/config.toml
[INFO] started tweaking crates.io crate ross-firmware 0.1.4
[INFO] finished tweaking crates.io crate ross-firmware 0.1.4
[INFO] tweaked toml for crates.io crate ross-firmware 0.1.4 written to /workspace/builds/worker-57/source/Cargo.toml
[INFO] crate crates.io crate ross-firmware 0.1.4 already has a lockfile, it will not be regenerated
[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-57/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-57/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] 5b172e4469f335a179e0656a1e6c4ffdc9cad193ef876d4c2f53997c20971755
[INFO] running `Command { std: "docker" "start" "-a" "5b172e4469f335a179e0656a1e6c4ffdc9cad193ef876d4c2f53997c20971755", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5b172e4469f335a179e0656a1e6c4ffdc9cad193ef876d4c2f53997c20971755", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b172e4469f335a179e0656a1e6c4ffdc9cad193ef876d4c2f53997c20971755", kill_on_drop: false }`
[INFO] [stdout] 5b172e4469f335a179e0656a1e6c4ffdc9cad193ef876d4c2f53997c20971755
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-57/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-57/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] 0adc2ad9c272c10d708b96bc2b097d150a8d6bd99b74bbc434435b885dfc42ff
[INFO] running `Command { std: "docker" "start" "-a" "0adc2ad9c272c10d708b96bc2b097d150a8d6bd99b74bbc434435b885dfc42ff", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.13.0
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling cortex-m v0.7.3
[INFO] [stderr]    Compiling semver v1.0.3
[INFO] [stderr]    Compiling heapless v0.5.6
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling defmt-parser v0.1.0
[INFO] [stderr]    Compiling cortex-m v0.6.7
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling cortex-m-rt v0.6.14
[INFO] [stderr]    Compiling stm32f1 v0.11.0
[INFO] [stderr]    Compiling r0 v0.2.2
[INFO] [stderr]    Compiling linked_list_allocator v0.8.11
[INFO] [stderr]    Compiling cobs v0.1.4
[INFO] [stderr]    Compiling nb v0.1.3
[INFO] [stderr]    Compiling embedded-can v0.3.0
[INFO] [stderr]    Compiling volatile-register v0.2.0
[INFO] [stderr]    Compiling embedded-dma v0.1.2
[INFO] [stderr]    Compiling embedded-hal v0.2.5
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]    Compiling hash32 v0.1.1
[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/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` 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" "0adc2ad9c272c10d708b96bc2b097d150a8d6bd99b74bbc434435b885dfc42ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0adc2ad9c272c10d708b96bc2b097d150a8d6bd99b74bbc434435b885dfc42ff", kill_on_drop: false }`
[INFO] [stdout] 0adc2ad9c272c10d708b96bc2b097d150a8d6bd99b74bbc434435b885dfc42ff