[INFO] fetching crate label 0.6.0...
[INFO] documenting label-0.6.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate label 0.6.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate label 0.6.0 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", 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-0/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" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bd6faa798519cb9032702be35cd78da65f62ef1da0e69a358b2f62524660af50
[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" "bd6faa798519cb9032702be35cd78da65f62ef1da0e69a358b2f62524660af50", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bd6faa798519cb9032702be35cd78da65f62ef1da0e69a358b2f62524660af50", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bd6faa798519cb9032702be35cd78da65f62ef1da0e69a358b2f62524660af50", kill_on_drop: false }`
[INFO] [stdout] bd6faa798519cb9032702be35cd78da65f62ef1da0e69a358b2f62524660af50
[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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 059c440fce4bb762ab0a17f57081ec6528735bc064e7cc346a2242bb11fcccd1
[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" "059c440fce4bb762ab0a17f57081ec6528735bc064e7cc346a2242bb11fcccd1", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.18
[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:2:1
[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`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "059c440fce4bb762ab0a17f57081ec6528735bc064e7cc346a2242bb11fcccd1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "059c440fce4bb762ab0a17f57081ec6528735bc064e7cc346a2242bb11fcccd1", kill_on_drop: false }`
[INFO] [stdout] 059c440fce4bb762ab0a17f57081ec6528735bc064e7cc346a2242bb11fcccd1