[INFO] fetching crate linked_list_allocator 0.9.1...
[INFO] testing linked_list_allocator-0.9.1 against 1.60.0 for beta-1.61-1
[INFO] extracting crate linked_list_allocator 0.9.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate linked_list_allocator 0.9.1 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-6/source/rust-toolchain
[INFO] started tweaking crates.io crate linked_list_allocator 0.9.1
[INFO] finished tweaking crates.io crate linked_list_allocator 0.9.1
[INFO] tweaked toml for crates.io crate linked_list_allocator 0.9.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 54dcf2c735cec59a65599571005048c7835e87285b4007f948a38fd6c7f9eb69
[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" "54dcf2c735cec59a65599571005048c7835e87285b4007f948a38fd6c7f9eb69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "54dcf2c735cec59a65599571005048c7835e87285b4007f948a38fd6c7f9eb69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54dcf2c735cec59a65599571005048c7835e87285b4007f948a38fd6c7f9eb69", kill_on_drop: false }`
[INFO] [stdout] 54dcf2c735cec59a65599571005048c7835e87285b4007f948a38fd6c7f9eb69
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "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] cdaf8f1295676eedaf8bce4bae65bc0cdf582656aa31d8ce8183df11eeaf73a2
[INFO] running `Command { std: "docker" "start" "-a" "cdaf8f1295676eedaf8bce4bae65bc0cdf582656aa31d8ce8183df11eeaf73a2", kill_on_drop: false }`
[INFO] [stderr]    Compiling lock_api v0.4.7
[INFO] [stderr]    Compiling spinning_top v0.2.4
[INFO] [stderr]    Compiling linked_list_allocator v0.9.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> 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] running `Command { std: "docker" "inspect" "cdaf8f1295676eedaf8bce4bae65bc0cdf582656aa31d8ce8183df11eeaf73a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cdaf8f1295676eedaf8bce4bae65bc0cdf582656aa31d8ce8183df11eeaf73a2", kill_on_drop: false }`
[INFO] [stdout] cdaf8f1295676eedaf8bce4bae65bc0cdf582656aa31d8ce8183df11eeaf73a2