[INFO] fetching crate neutron_kernel 0.1.1...
[INFO] testing neutron_kernel-0.1.1 against 1.90.0 for beta-1.91-3
[INFO] extracting crate neutron_kernel 0.1.1 into /workspace/builds/worker-1-tc1/source
[INFO] removed /workspace/builds/worker-1-tc1/source/.cargo/config.toml
[INFO] removed /workspace/builds/worker-1-tc1/source/rust-toolchain
[INFO] started tweaking crates.io crate neutron_kernel 0.1.1
[INFO] finished tweaking crates.io crate neutron_kernel 0.1.1
[INFO] tweaked toml for crates.io crate neutron_kernel 0.1.1 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate neutron_kernel 0.1.1 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 8 packages to latest compatible versions
[INFO] [stderr]       Adding linked_list_allocator v0.9.1 (available: v0.10.5)
[INFO] [stderr]       Adding spin v0.9.8 (available: v0.10.0)
[INFO] [stderr]       Adding volatile v0.4.6 (available: v0.6.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: the cargo feature `named-profiles` has been stabilized in the 1.57 release and is no longer necessary to be listed in the manifest
[INFO] [stderr]   See https://doc.rust-lang.org/cargo/reference/profiles.html#custom-profiles for more information about using this feature.
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded linked_list_allocator v0.9.1
[INFO] [stderr]   Downloaded volatile v0.4.6
[INFO] [stderr]   Downloaded spinning_top v0.2.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8a9606cbed93e68233ca3d1113dd96edf56953edf9de24ce6923a31d2e251cbf
[INFO] running `Command { std: "docker" "start" "-a" "8a9606cbed93e68233ca3d1113dd96edf56953edf9de24ce6923a31d2e251cbf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8a9606cbed93e68233ca3d1113dd96edf56953edf9de24ce6923a31d2e251cbf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8a9606cbed93e68233ca3d1113dd96edf56953edf9de24ce6923a31d2e251cbf", kill_on_drop: false }`
[INFO] [stdout] 8a9606cbed93e68233ca3d1113dd96edf56953edf9de24ce6923a31d2e251cbf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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" "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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5fe2dc7e1091146e002393e535a91d78073710902eb210b1519b713e78752cc5
[INFO] running `Command { std: "docker" "start" "-a" "5fe2dc7e1091146e002393e535a91d78073710902eb210b1519b713e78752cc5", kill_on_drop: false }`
[INFO] [stderr] warning: the cargo feature `named-profiles` has been stabilized in the 1.57 release and is no longer necessary to be listed in the manifest
[INFO] [stderr]   See https://doc.rust-lang.org/cargo/reference/profiles.html#custom-profiles for more information about using this feature.
[INFO] [stderr]    Compiling scopeguard v1.2.0
[INFO] [stderr]    Compiling volatile v0.4.6
[INFO] [stderr]    Compiling lock_api v0.4.13
[INFO] [stderr]    Compiling spinning_top v0.2.5
[INFO] [stderr]    Compiling spin v0.9.8
[INFO] [stderr]    Compiling linked_list_allocator v0.9.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/linked_list_allocator-0.9.1/src/lib.rs:1:41
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(feature = "const_mut_refs", feature(const_mut_refs))]
[INFO] [stdout]   |                                         ^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[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` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "5fe2dc7e1091146e002393e535a91d78073710902eb210b1519b713e78752cc5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5fe2dc7e1091146e002393e535a91d78073710902eb210b1519b713e78752cc5", kill_on_drop: false }`
[INFO] [stdout] 5fe2dc7e1091146e002393e535a91d78073710902eb210b1519b713e78752cc5