[INFO] cloning repository https://github.com/archer884/function_composition
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/archer884/function_composition" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farcher884%2Ffunction_composition", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farcher884%2Ffunction_composition'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7860c50fb5ea71d5131729f3d51c4b14e2042330
[INFO] documenting archer884/function_composition against beta-2021-08-01 for beta-1.55-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farcher884%2Ffunction_composition" "/workspace/builds/worker-106/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-106/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/archer884/function_composition on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/archer884/function_composition
[INFO] finished tweaking git repo https://github.com/archer884/function_composition
[INFO] tweaked toml for git repo https://github.com/archer884/function_composition written to /workspace/builds/worker-106/source/Cargo.toml
[INFO] crate git repo https://github.com/archer884/function_composition already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "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-106/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-106/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" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9224cd0a3fa8d323d4a56f9f6152a7aae26ac21569b8bfedc53daea95f9e1287
[INFO] running `Command { std: "docker" "start" "-a" "9224cd0a3fa8d323d4a56f9f6152a7aae26ac21569b8bfedc53daea95f9e1287", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9224cd0a3fa8d323d4a56f9f6152a7aae26ac21569b8bfedc53daea95f9e1287", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9224cd0a3fa8d323d4a56f9f6152a7aae26ac21569b8bfedc53daea95f9e1287", kill_on_drop: false }`
[INFO] [stdout] 9224cd0a3fa8d323d4a56f9f6152a7aae26ac21569b8bfedc53daea95f9e1287
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-106/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-106/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" "+beta-2021-08-01" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ad3e83530292a7f6c0b8f494dd9922f198a081347a69c84274f10495831b52bb
[INFO] running `Command { std: "docker" "start" "-a" "ad3e83530292a7f6c0b8f494dd9922f198a081347a69c84274f10495831b52bb", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Documenting function_composition v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_syntax)]
[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 `function_composition`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name function_composition src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "ad3e83530292a7f6c0b8f494dd9922f198a081347a69c84274f10495831b52bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad3e83530292a7f6c0b8f494dd9922f198a081347a69c84274f10495831b52bb", kill_on_drop: false }`
[INFO] [stdout] ad3e83530292a7f6c0b8f494dd9922f198a081347a69c84274f10495831b52bb
