[INFO] fetching crate alloc-cortex-m 0.4.2...
[INFO] documenting alloc-cortex-m-0.4.2 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate alloc-cortex-m 0.4.2 into /workspace/builds/worker-28/source
[INFO] validating manifest of crates.io crate alloc-cortex-m 0.4.2 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate alloc-cortex-m 0.4.2
[INFO] finished tweaking crates.io crate alloc-cortex-m 0.4.2
[INFO] tweaked toml for crates.io crate alloc-cortex-m 0.4.2 written to /workspace/builds/worker-28/source/Cargo.toml
[INFO] crate crates.io crate alloc-cortex-m 0.4.2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "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 linked_list_allocator v0.8.11
[INFO] [stderr]   Downloaded cortex-m-rt v0.6.13
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2f99389d9443113710fdec823f2467d0f188f39c97c29c395f4a1795f74c4caf
[INFO] running `Command { std: "docker" "start" "-a" "2f99389d9443113710fdec823f2467d0f188f39c97c29c395f4a1795f74c4caf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f99389d9443113710fdec823f2467d0f188f39c97c29c395f4a1795f74c4caf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f99389d9443113710fdec823f2467d0f188f39c97c29c395f4a1795f74c4caf", kill_on_drop: false }`
[INFO] [stdout] 2f99389d9443113710fdec823f2467d0f188f39c97c29c395f4a1795f74c4caf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/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" "RUSTDOCFLAGS=--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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 12eb0a5fafeaea292395d8323bc66feb2cc244f398054b33195e925f9147b574
[INFO] running `Command { std: "docker" "start" "-a" "12eb0a5fafeaea292395d8323bc66feb2cc244f398054b33195e925f9147b574", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[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/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] [stderr]     Checking nb v1.0.0
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling cortex-m v0.7.4
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr]     Checking vcell v0.1.3
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]     Checking linked_list_allocator v0.8.11
[INFO] [stderr]     Checking volatile-register v0.2.0
[INFO] [stderr]     Checking nb v0.1.3
[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] running `Command { std: "docker" "inspect" "12eb0a5fafeaea292395d8323bc66feb2cc244f398054b33195e925f9147b574", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12eb0a5fafeaea292395d8323bc66feb2cc244f398054b33195e925f9147b574", kill_on_drop: false }`
[INFO] [stdout] 12eb0a5fafeaea292395d8323bc66feb2cc244f398054b33195e925f9147b574