[INFO] cloning repository https://github.com/ithinuel/sandbox
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ithinuel/sandbox" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fithinuel%2Fsandbox", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fithinuel%2Fsandbox'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2851719ec975d9f75ec4baeb99cbc2d94da4bda7
[INFO] documenting ithinuel/sandbox 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%2Fithinuel%2Fsandbox" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ithinuel/sandbox 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/ithinuel/sandbox
[INFO] finished tweaking git repo https://github.com/ithinuel/sandbox
[INFO] tweaked toml for git repo https://github.com/ithinuel/sandbox written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/ithinuel/sandbox 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 5a5572d0892bf32307734f1efafec69784a2005dc44b503707c1882413efbf59
[INFO] running `Command { std: "docker" "start" "-a" "5a5572d0892bf32307734f1efafec69784a2005dc44b503707c1882413efbf59", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5a5572d0892bf32307734f1efafec69784a2005dc44b503707c1882413efbf59", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5a5572d0892bf32307734f1efafec69784a2005dc44b503707c1882413efbf59", kill_on_drop: false }`
[INFO] [stdout] 5a5572d0892bf32307734f1efafec69784a2005dc44b503707c1882413efbf59
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] d746441589a396167fa2cba7780344a965d9225d2c51a1ffd0eeff6a40dc7e75
[INFO] running `Command { std: "docker" "start" "-a" "d746441589a396167fa2cba7780344a965d9225d2c51a1ffd0eeff6a40dc7e75", kill_on_drop: false }`
[INFO] [stderr]     Checking num-traits v0.1.36
[INFO] [stderr]     Checking libc v0.2.17
[INFO] [stderr]     Checking rustc-serialize v0.3.21
[INFO] [stderr]     Checking rand v0.3.15
[INFO] [stderr]     Checking num_cpus v1.1.0
[INFO] [stderr]     Checking num-integer v0.1.32
[INFO] [stderr]     Checking num-iter v0.1.32
[INFO] [stderr]     Checking num-bigint v0.1.35
[INFO] [stderr]     Checking num-complex v0.1.35
[INFO] [stderr]     Checking num-rational v0.1.35
[INFO] [stderr]     Checking num v0.1.36
[INFO] [stderr]  Documenting sandbox 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(step_trait)]
[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 `sandbox`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name sandbox src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=63e005a352e70327 -L dependency=/opt/rustwide/target/debug/deps --extern num=/opt/rustwide/target/debug/deps/libnum-777c62f6b59961be.rmeta --extern num_cpus=/opt/rustwide/target/debug/deps/libnum_cpus-56b4d602f5a747bb.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "d746441589a396167fa2cba7780344a965d9225d2c51a1ffd0eeff6a40dc7e75", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d746441589a396167fa2cba7780344a965d9225d2c51a1ffd0eeff6a40dc7e75", kill_on_drop: false }`
[INFO] [stdout] d746441589a396167fa2cba7780344a965d9225d2c51a1ffd0eeff6a40dc7e75