[INFO] fetching crate cargo-minicov 0.1.1...
[INFO] documenting cargo-minicov-0.1.1 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate cargo-minicov 0.1.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate cargo-minicov 0.1.1 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 cargo-minicov 0.1.1
[INFO] finished tweaking crates.io crate cargo-minicov 0.1.1
[INFO] tweaked toml for crates.io crate cargo-minicov 0.1.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate cargo-minicov 0.1.1 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] [stderr]     Blocking waiting for file lock on package cache
[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" "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] 8a08c8d58fd701ffc0b0fde6ac4c0e4dc8bd08bf3616a1f2a33af982a6ecfdc0
[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" "8a08c8d58fd701ffc0b0fde6ac4c0e4dc8bd08bf3616a1f2a33af982a6ecfdc0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8a08c8d58fd701ffc0b0fde6ac4c0e4dc8bd08bf3616a1f2a33af982a6ecfdc0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8a08c8d58fd701ffc0b0fde6ac4c0e4dc8bd08bf3616a1f2a33af982a6ecfdc0", kill_on_drop: false }`
[INFO] [stdout] 8a08c8d58fd701ffc0b0fde6ac4c0e4dc8bd08bf3616a1f2a33af982a6ecfdc0
[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" "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] 2f1fd40ea66779af84c987448a93cc9f7f4412fc8679fd0db5e9f180af789c67
[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" "2f1fd40ea66779af84c987448a93cc9f7f4412fc8679fd0db5e9f180af789c67", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.10
[INFO] [stderr]    Compiling syn v1.0.17
[INFO] [stderr]    Compiling version_check v0.9.1
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]    Compiling unicode-segmentation v1.6.0
[INFO] [stderr]     Checking postcard-cobs v0.1.5-pre
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.2
[INFO] [stderr]    Compiling proc-macro-error v1.0.2
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling syn-mid v0.5.0
[INFO] [stderr]    Compiling serde_derive v1.0.106
[INFO] [stderr]    Compiling structopt-derive v0.4.6
[INFO] [stderr]     Checking structopt v0.3.13
[INFO] [stderr]     Checking postcard v0.5.0
[INFO] [stderr]  Documenting cargo-minicov v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(profiler_runtime_lib)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `cargo-minicov`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name cargo_minicov src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern postcard=/opt/rustwide/target/debug/deps/libpostcard-5b62813bd71befc7.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-04927ff4d69067ad.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-e9cca53f78c2bb23.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "2f1fd40ea66779af84c987448a93cc9f7f4412fc8679fd0db5e9f180af789c67", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f1fd40ea66779af84c987448a93cc9f7f4412fc8679fd0db5e9f180af789c67", kill_on_drop: false }`
[INFO] [stdout] 2f1fd40ea66779af84c987448a93cc9f7f4412fc8679fd0db5e9f180af789c67