[INFO] cloning repository https://github.com/cybermatt/fast-luhn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cybermatt/fast-luhn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcybermatt%2Ffast-luhn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcybermatt%2Ffast-luhn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3e0e61466d30166e95f4db15251c8e241c77ab29
[INFO] documenting cybermatt/fast-luhn against 1.54.0 for beta-1.55-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcybermatt%2Ffast-luhn" "/workspace/builds/worker-27/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-27/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/cybermatt/fast-luhn on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/cybermatt/fast-luhn
[INFO] finished tweaking git repo https://github.com/cybermatt/fast-luhn
[INFO] tweaked toml for git repo https://github.com/cybermatt/fast-luhn written to /workspace/builds/worker-27/source/Cargo.toml
[INFO] crate git repo https://github.com/cybermatt/fast-luhn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 43b275b3be6e9e61910f0f7dd76ce8203d779ee3e45f761f84d6c7f646a60471
[INFO] running `Command { std: "docker" "start" "-a" "43b275b3be6e9e61910f0f7dd76ce8203d779ee3e45f761f84d6c7f646a60471", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "43b275b3be6e9e61910f0f7dd76ce8203d779ee3e45f761f84d6c7f646a60471", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43b275b3be6e9e61910f0f7dd76ce8203d779ee3e45f761f84d6c7f646a60471", kill_on_drop: false }`
[INFO] [stdout] 43b275b3be6e9e61910f0f7dd76ce8203d779ee3e45f761f84d6c7f646a60471
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b27ae28251788f020c968f18016a835c1b9d7fb731d1cb581508238c03decbee
[INFO] running `Command { std: "docker" "start" "-a" "b27ae28251788f020c968f18016a835c1b9d7fb731d1cb581508238c03decbee", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.54
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling unindent v0.1.7
[INFO] [stderr]     Checking smallvec v1.5.1
[INFO] [stderr]    Compiling inventory v0.1.10
[INFO] [stderr]    Compiling pyo3 v0.12.4
[INFO] [stderr]     Checking instant v0.1.9
[INFO] [stderr]     Checking lock_api v0.4.2
[INFO] [stderr]     Checking rand_jitter v0.1.3
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking parking_lot_core v0.8.1
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling paste-impl v0.1.18
[INFO] [stderr]     Checking paste v0.1.18
[INFO] [stderr]    Compiling pyo3-derive-backend v0.12.4
[INFO] [stderr]    Compiling ctor v0.1.16
[INFO] [stderr]    Compiling ghost v0.1.2
[INFO] [stderr]    Compiling inventory-impl v0.1.10
[INFO] [stderr]    Compiling indoc-impl v0.3.6
[INFO] [stderr]    Compiling pyo3cls v0.12.4
[INFO] [stderr]     Checking indoc v0.3.6
[INFO] [stderr]  Documenting fast_luhn v0.1.5 (/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(specialization)]
[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 `fast_luhn`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type cdylib --crate-name fast_luhn 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 pyo3=/opt/rustwide/target/debug/deps/libpyo3-08fb05f0bba8de09.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-e4123019b0d9d502.rmeta --cap-lints=warn --crate-version 0.1.5` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "b27ae28251788f020c968f18016a835c1b9d7fb731d1cb581508238c03decbee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b27ae28251788f020c968f18016a835c1b9d7fb731d1cb581508238c03decbee", kill_on_drop: false }`
[INFO] [stdout] b27ae28251788f020c968f18016a835c1b9d7fb731d1cb581508238c03decbee
