[INFO] fetching crate reckon 0.1.0...
[INFO] documenting reckon-0.1.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate reckon 0.1.0 into /workspace/builds/worker-15/source
[INFO] validating manifest of crates.io crate reckon 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] started tweaking crates.io crate reckon 0.1.0
[INFO] finished tweaking crates.io crate reckon 0.1.0
[INFO] tweaked toml for crates.io crate reckon 0.1.0 written to /workspace/builds/worker-15/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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] bb81b375843d2baa1be6b9bd9970f86c9d35f62fb19a3ebdaca9a377ecbb4cf7
[INFO] running `Command { std: "docker" "start" "-a" "bb81b375843d2baa1be6b9bd9970f86c9d35f62fb19a3ebdaca9a377ecbb4cf7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bb81b375843d2baa1be6b9bd9970f86c9d35f62fb19a3ebdaca9a377ecbb4cf7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb81b375843d2baa1be6b9bd9970f86c9d35f62fb19a3ebdaca9a377ecbb4cf7", kill_on_drop: false }`
[INFO] [stdout] bb81b375843d2baa1be6b9bd9970f86c9d35f62fb19a3ebdaca9a377ecbb4cf7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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] 7ec9aff930728603677eb56ea58ac04f0fdffe8b4807ba95db7d531196d68d6b
[INFO] running `Command { std: "docker" "start" "-a" "7ec9aff930728603677eb56ea58ac04f0fdffe8b4807ba95db7d531196d68d6b", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]     Checking winapi v0.2.8
[INFO] [stderr]     Checking utf8-ranges v0.1.3
[INFO] [stderr]     Checking regex-syntax v0.3.9
[INFO] [stderr]    Compiling kernel32-sys v0.2.2
[INFO] [stderr]     Checking memchr v0.1.11
[INFO] [stderr]     Checking thread-id v2.0.0
[INFO] [stderr]     Checking thread_local v0.2.7
[INFO] [stderr]     Checking aho-corasick v0.5.3
[INFO] [stderr]     Checking regex v0.1.80
[INFO] [stderr]  Documenting reckon 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:9:12
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(io)]
[INFO] [stdout]   |            ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `io`
[INFO] [stdout]  --> src/lib.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(io)]
[INFO] [stdout]   |            ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0635.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `reckon`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name reckon src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=b83bd85b5f453376 -L dependency=/opt/rustwide/target/debug/deps --extern regex=/opt/rustwide/target/debug/deps/libregex-393c3f2879e969af.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "7ec9aff930728603677eb56ea58ac04f0fdffe8b4807ba95db7d531196d68d6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7ec9aff930728603677eb56ea58ac04f0fdffe8b4807ba95db7d531196d68d6b", kill_on_drop: false }`
[INFO] [stdout] 7ec9aff930728603677eb56ea58ac04f0fdffe8b4807ba95db7d531196d68d6b