[INFO] fetching crate eff 0.1.0...
[INFO] documenting eff-0.1.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate eff 0.1.0 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate eff 0.1.0 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 eff 0.1.0
[INFO] finished tweaking crates.io crate eff 0.1.0
[INFO] tweaked toml for crates.io crate eff 0.1.0 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate crates.io crate eff 0.1.0 already has a lockfile, it will not be regenerated
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 18471bba65bd151c50b17150dc2f6ceb1c5fd67f481444d98e16f6f614a7f4d0
[INFO] running `Command { std: "docker" "start" "-a" "18471bba65bd151c50b17150dc2f6ceb1c5fd67f481444d98e16f6f614a7f4d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "18471bba65bd151c50b17150dc2f6ceb1c5fd67f481444d98e16f6f614a7f4d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "18471bba65bd151c50b17150dc2f6ceb1c5fd67f481444d98e16f6f614a7f4d0", kill_on_drop: false }`
[INFO] [stdout] 18471bba65bd151c50b17150dc2f6ceb1c5fd67f481444d98e16f6f614a7f4d0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] 2b327cc5e3560d83751372045a09568da214c90ec1ed060b9d5754028bb0ccd7
[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" "2b327cc5e3560d83751372045a09568da214c90ec1ed060b9d5754028bb0ccd7", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]     Checking futures-core v0.3.1
[INFO] [stderr]     Checking spin v0.5.2
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking futures-channel v0.3.1
[INFO] [stderr]     Checking crossbeam-utils v0.7.0
[INFO] [stderr]     Checking crossbeam-channel v0.4.0
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling pin-project-internal v0.4.5
[INFO] [stderr]    Compiling futures-macro v0.3.1
[INFO] [stderr]    Compiling eff-attr v0.1.0
[INFO] [stderr]     Checking pin-project v0.4.5
[INFO] [stderr]     Checking futures-util v0.3.1
[INFO] [stderr]     Checking futures-executor v0.3.1
[INFO] [stderr]     Checking futures v0.3.1
[INFO] [stderr]  Documenting eff v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(generator_trait, never_type, stmt_expr_attributes, proc_macro_hygiene)]
[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 `eff`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name eff src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="futures"' --cfg 'feature="futures-compat"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern crossbeam_channel=/opt/rustwide/target/debug/deps/libcrossbeam_channel-19a143f30f2094bf.rmeta --extern eff_attr=/opt/rustwide/target/debug/deps/libeff_attr-afffa287b97bef7e.so --extern futures=/opt/rustwide/target/debug/deps/libfutures-36c189b69c875c8c.rmeta --extern pin_project=/opt/rustwide/target/debug/deps/libpin_project-c150a17265833501.rmeta --extern pin_utils=/opt/rustwide/target/debug/deps/libpin_utils-1e8347f3caf99ed9.rmeta --extern proc_macro_hack=/opt/rustwide/target/debug/deps/libproc_macro_hack-e1852c9b2a1bc2d4.so --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "2b327cc5e3560d83751372045a09568da214c90ec1ed060b9d5754028bb0ccd7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2b327cc5e3560d83751372045a09568da214c90ec1ed060b9d5754028bb0ccd7", kill_on_drop: false }`
[INFO] [stdout] 2b327cc5e3560d83751372045a09568da214c90ec1ed060b9d5754028bb0ccd7
