[INFO] fetching crate acon 0.5.1...
[INFO] documenting acon-0.5.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate acon 0.5.1 into /workspace/builds/worker-55/source
[INFO] validating manifest of crates.io crate acon 0.5.1 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 acon 0.5.1
[INFO] finished tweaking crates.io crate acon 0.5.1
[INFO] tweaked toml for crates.io crate acon 0.5.1 written to /workspace/builds/worker-55/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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] e58bff67fb1511a6116baa04fdb0007827074643ccf521dafaedb4b146c95cf6
[INFO] running `Command { std: "docker" "start" "-a" "e58bff67fb1511a6116baa04fdb0007827074643ccf521dafaedb4b146c95cf6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e58bff67fb1511a6116baa04fdb0007827074643ccf521dafaedb4b146c95cf6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e58bff67fb1511a6116baa04fdb0007827074643ccf521dafaedb4b146c95cf6", kill_on_drop: false }`
[INFO] [stdout] e58bff67fb1511a6116baa04fdb0007827074643ccf521dafaedb4b146c95cf6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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] 2864ed3302546c4e86fb6554495306dd8ad656537ea9f0aac21fda3704f93eae
[INFO] running `Command { std: "docker" "start" "-a" "2864ed3302546c4e86fb6554495306dd8ad656537ea9f0aac21fda3704f93eae", kill_on_drop: false }`
[INFO] [stderr]  Documenting acon v0.5.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> src/lib.rs:110:12
[INFO] [stdout]     |
[INFO] [stdout] 110 | #![feature(test)]
[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 `acon`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name acon src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=fbd6b744b9cf50b9 -L dependency=/opt/rustwide/target/debug/deps --cap-lints=warn --crate-version 0.5.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "2864ed3302546c4e86fb6554495306dd8ad656537ea9f0aac21fda3704f93eae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2864ed3302546c4e86fb6554495306dd8ad656537ea9f0aac21fda3704f93eae", kill_on_drop: false }`
[INFO] [stdout] 2864ed3302546c4e86fb6554495306dd8ad656537ea9f0aac21fda3704f93eae