[INFO] cloning repository https://github.com/vorner/fade
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/vorner/fade" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvorner%2Ffade", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvorner%2Ffade'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9410927523be717fefc152a4ade78a1baff8163d
[INFO] documenting vorner/fade against 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvorner%2Ffade" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/vorner/fade 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] started tweaking git repo https://github.com/vorner/fade
[INFO] finished tweaking git repo https://github.com/vorner/fade
[INFO] tweaked toml for git repo https://github.com/vorner/fade written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/vorner/fade 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded quote v1.0.8
[INFO] [stderr]   Downloaded rand_hc v0.3.0
[INFO] [stderr]   Downloaded crossbeam-epoch v0.9.1
[INFO] [stderr]   Downloaded rand_core v0.6.1
[INFO] [stderr]   Downloaded crossbeam-channel v0.5.0
[INFO] [stderr]   Downloaded rand_chacha v0.3.0
[INFO] [stderr]   Downloaded memoffset v0.6.1
[INFO] [stderr]   Downloaded wasi v0.10.1+wasi-snapshot-preview1
[INFO] [stderr]   Downloaded rayon v1.5.0
[INFO] [stderr]   Downloaded syn v1.0.58
[INFO] [stderr]   Downloaded libc v0.2.82
[INFO] [stderr]   Downloaded crossbeam-utils v0.8.1
[INFO] [stderr]   Downloaded rand v0.8.2
[INFO] [stderr]   Downloaded rayon-core v1.9.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 1656a7b0c75fdc3b63ed20665cc3325f52c3617dbde2ee7567022e57d6f611ae
[INFO] running `Command { std: "docker" "start" "-a" "1656a7b0c75fdc3b63ed20665cc3325f52c3617dbde2ee7567022e57d6f611ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1656a7b0c75fdc3b63ed20665cc3325f52c3617dbde2ee7567022e57d6f611ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1656a7b0c75fdc3b63ed20665cc3325f52c3617dbde2ee7567022e57d6f611ae", kill_on_drop: false }`
[INFO] [stdout] 1656a7b0c75fdc3b63ed20665cc3325f52c3617dbde2ee7567022e57d6f611ae
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] e0ad990f0c82a4252bb9ed4215d9751b8818a472ecab89862fcd6ecd4325bf81
[INFO] running `Command { std: "docker" "start" "-a" "e0ad990f0c82a4252bb9ed4215d9751b8818a472ecab89862fcd6ecd4325bf81", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.82
[INFO] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.58
[INFO] [stderr]    Compiling const_fn v0.4.5
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling rayon-core v1.9.0
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling unicode-segmentation v1.7.1
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]    Compiling heck v0.3.2
[INFO] [stderr]    Compiling crossbeam-utils v0.8.1
[INFO] [stderr]    Compiling memoffset v0.6.1
[INFO] [stderr]    Compiling rayon v1.5.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling generic-array v0.14.4
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking rand_core v0.6.1
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.2
[INFO] [stderr]     Checking crossbeam-epoch v0.9.1
[INFO] [stderr]     Checking crossbeam-channel v0.5.0
[INFO] [stderr]     Checking slipstream v0.1.1
[INFO] [stderr]     Checking crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling multiversion-macros v0.6.1
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]     Checking multiversion v0.6.1
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]  Documenting fade v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(bench_black_box)]
[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 document `fade`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name fade src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=654a450d573f2a80 -L dependency=/opt/rustwide/target/debug/deps --extern multiversion=/opt/rustwide/target/debug/deps/libmultiversion-811ee7beabd1c711.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-bec507d80687e627.rmeta --extern rayon=/opt/rustwide/target/debug/deps/librayon-49d62df79ef0cdbb.rmeta --extern slipstream=/opt/rustwide/target/debug/deps/libslipstream-f87f5df5c70e1ad4.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-1fa30fcbe8bc8e2f.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "e0ad990f0c82a4252bb9ed4215d9751b8818a472ecab89862fcd6ecd4325bf81", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e0ad990f0c82a4252bb9ed4215d9751b8818a472ecab89862fcd6ecd4325bf81", kill_on_drop: false }`
[INFO] [stdout] e0ad990f0c82a4252bb9ed4215d9751b8818a472ecab89862fcd6ecd4325bf81