[INFO] fetching crate alloc-cortex-m 0.4.0...
[INFO] checking alloc-cortex-m-0.4.0 against master#a609fb45efad59dfd459c76e50899be9f0583b5a for pr-80579
[INFO] extracting crate alloc-cortex-m 0.4.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate alloc-cortex-m 0.4.0 on toolchain a609fb45efad59dfd459c76e50899be9f0583b5a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate alloc-cortex-m 0.4.0
[INFO] finished tweaking crates.io crate alloc-cortex-m 0.4.0
[INFO] tweaked toml for crates.io crate alloc-cortex-m 0.4.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate alloc-cortex-m 0.4.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "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-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a68113f154b420c1ea498e1eaca4fe5ce908e62b38d8f15880b05fc23831f8a
[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" "1a68113f154b420c1ea498e1eaca4fe5ce908e62b38d8f15880b05fc23831f8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a68113f154b420c1ea498e1eaca4fe5ce908e62b38d8f15880b05fc23831f8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a68113f154b420c1ea498e1eaca4fe5ce908e62b38d8f15880b05fc23831f8a", kill_on_drop: false }`
[INFO] [stdout] 1a68113f154b420c1ea498e1eaca4fe5ce908e62b38d8f15880b05fc23831f8a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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=forbid" "-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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8ca35d3456103e1f39621c58ce208ac349a54d619d92cb7e1d0b5f7dee4c4bfd
[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" "8ca35d3456103e1f39621c58ce208ac349a54d619d92cb7e1d0b5f7dee4c4bfd", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.12
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.19
[INFO] [stderr]     Checking stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling cortex-m v0.6.2
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]     Checking linked_list_allocator v0.8.4
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]     Checking as-slice v0.1.3
[INFO] [stdout] error[E0658]: mutable references are not allowed in constant functions
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/linked_list_allocator-0.8.4/src/hole.rs:18:23
[INFO] [stdout]    |
[INFO] [stdout] 18 |                 next: None,
[INFO] [stdout]    |                       ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
[INFO] [stdout]    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
[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 E0658`.
[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" "8ca35d3456103e1f39621c58ce208ac349a54d619d92cb7e1d0b5f7dee4c4bfd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ca35d3456103e1f39621c58ce208ac349a54d619d92cb7e1d0b5f7dee4c4bfd", kill_on_drop: false }`
[INFO] [stdout] 8ca35d3456103e1f39621c58ce208ac349a54d619d92cb7e1d0b5f7dee4c4bfd