[INFO] fetching crate mantle 0.2.1...
[INFO] documenting mantle-0.2.1 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate mantle 0.2.1 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate mantle 0.2.1 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 mantle 0.2.1
[INFO] finished tweaking crates.io crate mantle 0.2.1
[INFO] tweaked toml for crates.io crate mantle 0.2.1 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] a00ff7a9e06fc684722ee71a72da80ce0febf898c4a16a772c0ffc1e81b610fc
[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" "a00ff7a9e06fc684722ee71a72da80ce0febf898c4a16a772c0ffc1e81b610fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a00ff7a9e06fc684722ee71a72da80ce0febf898c4a16a772c0ffc1e81b610fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a00ff7a9e06fc684722ee71a72da80ce0febf898c4a16a772c0ffc1e81b610fc", kill_on_drop: false }`
[INFO] [stdout] a00ff7a9e06fc684722ee71a72da80ce0febf898c4a16a772c0ffc1e81b610fc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] b0b8969072fe4a2cc59457c9fee3c28da5926c45eaecf709f2443267855ff464
[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" "b0b8969072fe4a2cc59457c9fee3c28da5926c45eaecf709f2443267855ff464", kill_on_drop: false }`
[INFO] [stderr]    Compiling thiserror-impl v1.0.20
[INFO] [stderr]     Checking serde_cbor v0.10.2
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-quote-impl v0.2.2
[INFO] [stderr]     Checking thiserror v1.0.20
[INFO] [stderr]    Compiling proc-quote v0.2.2
[INFO] [stderr]    Compiling derive_more v0.15.0
[INFO] [stderr]    Compiling default-env v0.1.1
[INFO] [stderr]    Compiling mantle-macros v0.2.1
[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/mantle-macros-0.2.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_diagnostic, type_ascription)]
[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 `mantle-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" "b0b8969072fe4a2cc59457c9fee3c28da5926c45eaecf709f2443267855ff464", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b0b8969072fe4a2cc59457c9fee3c28da5926c45eaecf709f2443267855ff464", kill_on_drop: false }`
[INFO] [stdout] b0b8969072fe4a2cc59457c9fee3c28da5926c45eaecf709f2443267855ff464