[INFO] cloning repository https://github.com/iohub/piece
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/iohub/piece" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiohub%2Fpiece", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiohub%2Fpiece'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2435d7c783184f70c410675578b16fbfc6330da2
[INFO] documenting iohub/piece against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiohub%2Fpiece" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/iohub/piece on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/iohub/piece
[INFO] finished tweaking git repo https://github.com/iohub/piece
[INFO] tweaked toml for git repo https://github.com/iohub/piece written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/iohub/piece already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded llvm-sys v60.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] abbaa29debe70b49cdefbeb75e48b82fa8da9dd77273dcdbbcd3a19d4d739ac0
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "abbaa29debe70b49cdefbeb75e48b82fa8da9dd77273dcdbbcd3a19d4d739ac0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "abbaa29debe70b49cdefbeb75e48b82fa8da9dd77273dcdbbcd3a19d4d739ac0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "abbaa29debe70b49cdefbeb75e48b82fa8da9dd77273dcdbbcd3a19d4d739ac0", kill_on_drop: false }`
[INFO] [stdout] abbaa29debe70b49cdefbeb75e48b82fa8da9dd77273dcdbbcd3a19d4d739ac0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b1bd36e69b7685f129029519445054be4002d753203bfb6de0287a06a95822d7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b1bd36e69b7685f129029519445054be4002d753203bfb6de0287a06a95822d7", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling ucd-util v0.1.3
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling utf8-ranges v1.0.2
[INFO] [stderr]    Compiling byteorder v1.3.1
[INFO] [stderr]    Compiling serde v1.0.89
[INFO] [stderr]    Compiling regex v1.1.2
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling cfg-if v0.1.7
[INFO] [stderr]    Compiling strsim v0.7.0
[INFO] [stderr]    Compiling new_debug_unreachable v1.0.3
[INFO] [stderr]    Compiling either v1.5.1
[INFO] [stderr]    Compiling opaque-debug v0.2.2
[INFO] [stderr]    Compiling bit-vec v0.5.0
[INFO] [stderr]    Compiling fixedbitset v0.1.9
[INFO] [stderr]    Compiling precomputed-hash v0.1.1
[INFO] [stderr]    Compiling fake-simd v0.1.2
[INFO] [stderr]    Compiling ordermap v0.3.5
[INFO] [stderr]    Compiling term v0.4.6
[INFO] [stderr]    Compiling cc v1.0.35
[INFO] [stderr]    Compiling lalrpop-util v0.16.3
[INFO] [stderr]    Compiling diff v0.1.11
[INFO] [stderr]    Compiling block-padding v0.1.3
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[INFO] [stderr]    Compiling regex-syntax v0.6.5
[INFO] [stderr]    Compiling itertools v0.8.0
[INFO] [stderr]    Compiling bit-set v0.5.0
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]    Compiling typenum v1.10.0
[INFO] [stderr]    Compiling ena v0.11.0
[INFO] [stderr]    Compiling petgraph v0.4.13
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling syn v0.15.27
[INFO] [stderr]    Compiling ascii-canvas v1.0.0
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]    Compiling string_cache_codegen v0.4.2
[INFO] [stderr]    Compiling generic-array v0.12.0
[INFO] [stderr]    Compiling string_cache v0.7.3
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling digest v0.8.0
[INFO] [stderr]    Compiling sha2 v0.8.0
[INFO] [stderr]     Checking regex v0.2.11
[INFO] [stderr]    Compiling serde_derive v1.0.89
[INFO] [stderr]    Compiling llvm-sys v60.3.0
[INFO] [stderr]    Compiling docopt v1.0.2
[INFO] [stderr]    Compiling lalrpop v0.16.3
[INFO] [stderr]    Compiling do-lang v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting do-lang v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:16144:5
[INFO] [stdout]       |
[INFO] [stdout] 16144 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout]       |
[INFO] [stdout]       = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:16155:5
[INFO] [stdout]       |
[INFO] [stdout] 16155 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:16166:5
[INFO] [stdout]       |
[INFO] [stdout] 16166 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:17246:5
[INFO] [stdout]       |
[INFO] [stdout] 17246 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:17304:5
[INFO] [stdout]       |
[INFO] [stdout] 17304 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:17380:5
[INFO] [stdout]       |
[INFO] [stdout] 17380 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:17414:5
[INFO] [stdout]       |
[INFO] [stdout] 17414 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]      --> /opt/rustwide/target/debug/build/do-lang-6adf6aef78847372/out/grammar.rs:17553:5
[INFO] [stdout]       |
[INFO] [stdout] 17553 |     (__0)
[INFO] [stdout]       |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2m 09s
[INFO] running `Command { std: "docker" "inspect" "b1bd36e69b7685f129029519445054be4002d753203bfb6de0287a06a95822d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b1bd36e69b7685f129029519445054be4002d753203bfb6de0287a06a95822d7", kill_on_drop: false }`
[INFO] [stdout] b1bd36e69b7685f129029519445054be4002d753203bfb6de0287a06a95822d7