[INFO] fetching crate eff 0.1.0...
[INFO] documenting eff-0.1.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate eff 0.1.0 into /workspace/builds/worker-107/source
[INFO] validating manifest of crates.io crate eff 0.1.0 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-107/source/rust-toolchain
[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-107/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" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio-codec v0.2.0-alpha.6
[INFO] [stderr]   Downloaded pin-project v0.4.5
[INFO] [stderr]   Downloaded tokio-io v0.2.0-alpha.6
[INFO] [stderr]   Downloaded futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded crossbeam-channel v0.4.0
[INFO] [stderr]   Downloaded tokio-net v0.2.0-alpha.6
[INFO] [stderr]   Downloaded tokio-fs v0.2.0-alpha.6
[INFO] [stderr]   Downloaded lock_api v0.3.1
[INFO] [stderr]   Downloaded tracing-core v0.1.7
[INFO] [stderr]   Downloaded tracing v0.1.10
[INFO] [stderr]   Downloaded pin-project-internal v0.4.5
[INFO] [stderr]   Downloaded tokio v0.2.0-alpha.6
[INFO] [stderr]   Downloaded syn v1.0.8
[INFO] [stderr]   Downloaded eff-attr v0.1.0
[INFO] [stderr]   Downloaded tokio-macros v0.2.0-alpha.6
[INFO] [stderr]   Downloaded tokio-sync v0.2.0-alpha.6
[INFO] [stderr]   Downloaded tokio-executor v0.2.0-alpha.6
[INFO] [stderr]   Downloaded tokio-timer v0.3.0-alpha.6
[INFO] [stderr]   Downloaded futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded tracing-attributes v0.1.5
[INFO] [stderr]   Downloaded futures-sink-preview v0.3.0-alpha.19
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3cd52b4919d2c3dcf4c199f737e066abe62cc28bbc87419e244f42973e8bf530
[INFO] running `Command { std: "docker" "start" "-a" "3cd52b4919d2c3dcf4c199f737e066abe62cc28bbc87419e244f42973e8bf530", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3cd52b4919d2c3dcf4c199f737e066abe62cc28bbc87419e244f42973e8bf530", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3cd52b4919d2c3dcf4c199f737e066abe62cc28bbc87419e244f42973e8bf530", kill_on_drop: false }`
[INFO] [stdout] 3cd52b4919d2c3dcf4c199f737e066abe62cc28bbc87419e244f42973e8bf530
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 27c4918ab6eed46859a9029cde91119bb289b26448251d7001f3dac34275b837
[INFO] running `Command { std: "docker" "start" "-a" "27c4918ab6eed46859a9029cde91119bb289b26448251d7001f3dac34275b837", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.6
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]     Checking futures-sink v0.3.1
[INFO] [stderr]     Checking futures-core v0.3.1
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]     Checking futures-io v0.3.1
[INFO] [stderr]     Checking futures-task v0.3.1
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]     Checking spin v0.5.2
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking futures-channel v0.3.1
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling crossbeam-utils v0.7.0
[INFO] [stderr]    Compiling quote v1.0.2
[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,artifacts,future-incompat --document-private-items -C metadata=f783f9c4f23dd732 -L dependency=/opt/rustwide/target/debug/deps --extern crossbeam_channel=/opt/rustwide/target/debug/deps/libcrossbeam_channel-c82db8d26cad4350.rmeta --extern eff_attr=/opt/rustwide/target/debug/deps/libeff_attr-fda067d357d3a4ff.so --extern futures=/opt/rustwide/target/debug/deps/libfutures-18319fc211538e30.rmeta --extern pin_project=/opt/rustwide/target/debug/deps/libpin_project-758208dd8260e525.rmeta --extern pin_utils=/opt/rustwide/target/debug/deps/libpin_utils-6c182d5e604fead1.rmeta --extern proc_macro_hack=/opt/rustwide/target/debug/deps/libproc_macro_hack-a879bab0d9f2a321.so --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "27c4918ab6eed46859a9029cde91119bb289b26448251d7001f3dac34275b837", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "27c4918ab6eed46859a9029cde91119bb289b26448251d7001f3dac34275b837", kill_on_drop: false }`
[INFO] [stdout] 27c4918ab6eed46859a9029cde91119bb289b26448251d7001f3dac34275b837