[INFO] fetching crate alkyn 0.0.1...
[INFO] testing alkyn-0.0.1 against 1.60.0 for beta-1.61-1
[INFO] extracting crate alkyn 0.0.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate alkyn 0.0.1 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-2/source/.cargo/config.toml
[INFO] removed /workspace/builds/worker-2/source/rust-toolchain
[INFO] started tweaking crates.io crate alkyn 0.0.1
[INFO] finished tweaking crates.io crate alkyn 0.0.1
[INFO] tweaked toml for crates.io crate alkyn 0.0.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate alkyn 0.0.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rp2040-hal v0.4.0
[INFO] [stderr]   Downloaded rp2040-boot2 v0.2.0
[INFO] [stderr]   Downloaded rp2040-pac v0.3.0
[INFO] [stderr]   Downloaded defmt-macros v0.3.1
[INFO] [stderr]   Downloaded defmt-rtt v0.3.1
[INFO] [stderr]   Downloaded panic-probe v0.3.0
[INFO] [stderr]   Downloaded debug-helper v0.3.12
[INFO] [stderr]   Downloaded critical-section v0.2.5
[INFO] [stderr]   Downloaded pio v0.2.0
[INFO] [stderr]   Downloaded usb-device v0.2.8
[INFO] [stderr]   Downloaded crc-any v2.4.1
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6b6a08040d2829e1ba77698883da2e1d61849af86645eae3242777aa1a6043db
[INFO] running `Command { std: "docker" "start" "-a" "6b6a08040d2829e1ba77698883da2e1d61849af86645eae3242777aa1a6043db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b6a08040d2829e1ba77698883da2e1d61849af86645eae3242777aa1a6043db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b6a08040d2829e1ba77698883da2e1d61849af86645eae3242777aa1a6043db", kill_on_drop: false }`
[INFO] [stdout] 6b6a08040d2829e1ba77698883da2e1d61849af86645eae3242777aa1a6043db
[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=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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5031befe2f817537989c6bba3179a0aa5ebc793f5e7aa68b8ea10a341cc9ff2e
[INFO] running `Command { std: "docker" "start" "-a" "5031befe2f817537989c6bba3179a0aa5ebc793f5e7aa68b8ea10a341cc9ff2e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v1.0.36
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling cortex-m v0.7.4
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling defmt v0.3.0
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling cortex-m-rt v0.7.1
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.8
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling defmt-macros v0.3.1
[INFO] [stderr]    Compiling debug-helper v0.3.12
[INFO] [stderr]    Compiling defmt-parser v0.3.0
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling crossbeam-queue v0.3.5
[INFO] [stderr]    Compiling rp2040-pac v0.3.0
[INFO] [stderr]    Compiling critical-section v0.2.5
[INFO] [stderr]    Compiling panic-probe v0.3.0
[INFO] [stderr]    Compiling paste v1.0.6
[INFO] [stderr]    Compiling bare-metal v1.0.0
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling arrayvec v0.7.2
[INFO] [stderr]    Compiling defmt-rtt v0.3.1
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling usb-device v0.2.8
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling alkyn v0.0.1 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling linked_list_allocator v0.8.11
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-rational v0.3.2
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.8
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling memoffset v0.6.5
[INFO] [stderr]    Compiling volatile-register v0.2.1
[INFO] [stderr]    Compiling crc-any v2.4.1
[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] [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" "5031befe2f817537989c6bba3179a0aa5ebc793f5e7aa68b8ea10a341cc9ff2e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5031befe2f817537989c6bba3179a0aa5ebc793f5e7aa68b8ea10a341cc9ff2e", kill_on_drop: false }`
[INFO] [stdout] 5031befe2f817537989c6bba3179a0aa5ebc793f5e7aa68b8ea10a341cc9ff2e