[INFO] fetching crate label 0.6.0...
[INFO] documenting label-0.6.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate label 0.6.0 into /workspace/builds/worker-33/source
[INFO] validating manifest of crates.io crate label 0.6.0 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] started tweaking crates.io crate label 0.6.0
[INFO] finished tweaking crates.io crate label 0.6.0
[INFO] tweaked toml for crates.io crate label 0.6.0 written to /workspace/builds/worker-33/source/Cargo.toml
[INFO] crate crates.io crate label 0.6.0 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 label-macros v0.6.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/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] 36d3ae127d16b62fb1b1340f656cf7cbfffaaa8f214a63a92b4861711ffe3c18
[INFO] running `Command { std: "docker" "start" "-a" "36d3ae127d16b62fb1b1340f656cf7cbfffaaa8f214a63a92b4861711ffe3c18", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "36d3ae127d16b62fb1b1340f656cf7cbfffaaa8f214a63a92b4861711ffe3c18", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "36d3ae127d16b62fb1b1340f656cf7cbfffaaa8f214a63a92b4861711ffe3c18", kill_on_drop: false }`
[INFO] [stdout] 36d3ae127d16b62fb1b1340f656cf7cbfffaaa8f214a63a92b4861711ffe3c18
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/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] 5d4c50e707ba56e5807520794849a8ae9600b8523ab37d1fb565a46f0de234f9
[INFO] running `Command { std: "docker" "start" "-a" "5d4c50e707ba56e5807520794849a8ae9600b8523ab37d1fb565a46f0de234f9", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.18
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.33
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling label-macros v0.6.0
[INFO] [stderr]    Compiling ctor v0.1.15
[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/label-macros-0.6.0/src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(proc_macro_span)]
[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 `label-macros` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "5d4c50e707ba56e5807520794849a8ae9600b8523ab37d1fb565a46f0de234f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5d4c50e707ba56e5807520794849a8ae9600b8523ab37d1fb565a46f0de234f9", kill_on_drop: false }`
[INFO] [stdout] 5d4c50e707ba56e5807520794849a8ae9600b8523ab37d1fb565a46f0de234f9