[INFO] fetching crate meio 0.8.0...
[INFO] documenting meio-0.8.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate meio 0.8.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate meio 0.8.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate meio 0.8.0
[INFO] finished tweaking crates.io crate meio 0.8.0
[INFO] tweaked toml for crates.io crate meio 0.8.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c3fd1edbab0f21cc82d3b5781007671754250b065fe045a24d08731f844648bd
[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" "c3fd1edbab0f21cc82d3b5781007671754250b065fe045a24d08731f844648bd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c3fd1edbab0f21cc82d3b5781007671754250b065fe045a24d08731f844648bd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c3fd1edbab0f21cc82d3b5781007671754250b065fe045a24d08731f844648bd", kill_on_drop: false }`
[INFO] [stdout] c3fd1edbab0f21cc82d3b5781007671754250b065fe045a24d08731f844648bd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ae3353aa8eb971c021430147a03515773635829ccbe8c72658508d0d564aaa87
[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" "ae3353aa8eb971c021430147a03515773635829ccbe8c72658508d0d564aaa87", kill_on_drop: false }`
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling derive_more v0.99.11
[INFO] [stderr]    Compiling async-trait v0.1.41
[INFO] [stderr]     Checking futures-util v0.3.6
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stderr]     Checking futures-executor v0.3.6
[INFO] [stderr]     Checking futures v0.3.6
[INFO] [stderr]  Documenting meio v0.8.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:13:1
[INFO] [stdout]    |
[INFO] [stdout] 13 | #![feature(generators)]
[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 `meio`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name meio src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern anyhow=/opt/rustwide/target/debug/deps/libanyhow-e8218b22857a1d1d.rmeta --extern async_trait=/opt/rustwide/target/debug/deps/libasync_trait-424eb084ed03371c.so --extern derive_more=/opt/rustwide/target/debug/deps/libderive_more-f956264cc7174e38.so --extern futures=/opt/rustwide/target/debug/deps/libfutures-c49474a22ff312d4.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-48fbfd5d624c4cb9.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-a556f20d08de025c.rmeta --extern uuid=/opt/rustwide/target/debug/deps/libuuid-dd1a5ac6c5f4249d.rmeta --cap-lints=warn --crate-version 0.8.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "ae3353aa8eb971c021430147a03515773635829ccbe8c72658508d0d564aaa87", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ae3353aa8eb971c021430147a03515773635829ccbe8c72658508d0d564aaa87", kill_on_drop: false }`
[INFO] [stdout] ae3353aa8eb971c021430147a03515773635829ccbe8c72658508d0d564aaa87
