[INFO] fetching crate alkyn 0.0.3...
[INFO] documenting alkyn-0.0.3 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate alkyn 0.0.3 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate alkyn 0.0.3 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] removed /workspace/builds/worker-0/source/.cargo/config.toml
[INFO] removed /workspace/builds/worker-0/source/rust-toolchain
[INFO] started tweaking crates.io crate alkyn 0.0.3
[INFO] finished tweaking crates.io crate alkyn 0.0.3
[INFO] tweaked toml for crates.io crate alkyn 0.0.3 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate alkyn 0.0.3 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 pio v0.2.0
[INFO] [stderr]   Downloaded rp2040-boot2 v0.2.0
[INFO] [stderr]   Downloaded panic-probe v0.3.0
[INFO] [stderr]   Downloaded crc-any v2.4.1
[INFO] [stderr]   Downloaded rp2040-hal v0.4.0
[INFO] [stderr]   Downloaded defmt-rtt v0.3.1
[INFO] [stderr]   Downloaded defmt-macros v0.3.1
[INFO] [stderr]   Downloaded rp2040-pac v0.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] b4afc817c31c892b251c848685162f9602298affa2610c03e672697a35a2fe1a
[INFO] running `Command { std: "docker" "start" "-a" "b4afc817c31c892b251c848685162f9602298affa2610c03e672697a35a2fe1a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b4afc817c31c892b251c848685162f9602298affa2610c03e672697a35a2fe1a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b4afc817c31c892b251c848685162f9602298affa2610c03e672697a35a2fe1a", kill_on_drop: false }`
[INFO] [stdout] b4afc817c31c892b251c848685162f9602298affa2610c03e672697a35a2fe1a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 03e51638903dde8a1e6170bd51ebc6868a2f0dcbed5fa9f645dbbf0ae6ed9623
[INFO] running `Command { std: "docker" "start" "-a" "03e51638903dde8a1e6170bd51ebc6868a2f0dcbed5fa9f645dbbf0ae6ed9623", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.36
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling cortex-m v0.7.4
[INFO] [stderr]    Compiling version_check v0.9.4
[INFO] [stderr]    Compiling defmt v0.3.0
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking vcell v0.1.3
[INFO] [stderr]    Compiling cortex-m-rt v0.7.1
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]    Compiling defmt-macros v0.3.1
[INFO] [stderr]    Compiling defmt-parser v0.3.0
[INFO] [stderr]    Compiling debug-helper v0.3.12
[INFO] [stderr]    Compiling rp2040-pac v0.3.0
[INFO] [stderr]    Compiling critical-section v0.2.5
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking arrayvec v0.7.2
[INFO] [stderr]    Compiling panic-probe v0.3.0
[INFO] [stderr]    Compiling paste v1.0.6
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling defmt-rtt v0.3.1
[INFO] [stderr]     Checking bare-metal v1.0.0
[INFO] [stderr]    Compiling alkyn v0.0.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking usb-device v0.2.8
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking linked_list_allocator v0.8.11
[INFO] [stderr]     Checking volatile-register v0.2.1
[INFO] [stderr]     Checking nb v0.1.3
[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] running `Command { std: "docker" "inspect" "03e51638903dde8a1e6170bd51ebc6868a2f0dcbed5fa9f645dbbf0ae6ed9623", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03e51638903dde8a1e6170bd51ebc6868a2f0dcbed5fa9f645dbbf0ae6ed9623", kill_on_drop: false }`
[INFO] [stdout] 03e51638903dde8a1e6170bd51ebc6868a2f0dcbed5fa9f645dbbf0ae6ed9623