[INFO] cloning repository https://github.com/shenril/rustlings-solutions
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/shenril/rustlings-solutions" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshenril%2Frustlings-solutions", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshenril%2Frustlings-solutions'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 864190633884cff5661c0bb8c30b1980af187d6b
[INFO] documenting shenril/rustlings-solutions against master#d7d9f15be205b45d44700e7ac33b4f79b91f9680 for pr-117450
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshenril%2Frustlings-solutions" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/shenril/rustlings-solutions on toolchain d7d9f15be205b45d44700e7ac33b4f79b91f9680
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d7d9f15be205b45d44700e7ac33b4f79b91f9680" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/shenril/rustlings-solutions
[INFO] finished tweaking git repo https://github.com/shenril/rustlings-solutions
[INFO] tweaked toml for git repo https://github.com/shenril/rustlings-solutions written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/shenril/rustlings-solutions already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d7d9f15be205b45d44700e7ac33b4f79b91f9680" "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
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] documenting shenril/rustlings-solutions against master#50be22964035027398754e54cd3a497efb00f83e for pr-117450
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshenril%2Frustlings-solutions" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/shenril/rustlings-solutions on toolchain 50be22964035027398754e54cd3a497efb00f83e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50be22964035027398754e54cd3a497efb00f83e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/shenril/rustlings-solutions
[INFO] finished tweaking git repo https://github.com/shenril/rustlings-solutions
[INFO] tweaked toml for git repo https://github.com/shenril/rustlings-solutions written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/shenril/rustlings-solutions already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50be22964035027398754e54cd3a497efb00f83e" "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
[ERROR] error running command: no output for 300 seconds
[INFO] documenting shenril/rustlings-solutions against master#50be22964035027398754e54cd3a497efb00f83e for pr-117450
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshenril%2Frustlings-solutions" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/shenril/rustlings-solutions on toolchain 50be22964035027398754e54cd3a497efb00f83e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50be22964035027398754e54cd3a497efb00f83e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/shenril/rustlings-solutions
[INFO] finished tweaking git repo https://github.com/shenril/rustlings-solutions
[INFO] tweaked toml for git repo https://github.com/shenril/rustlings-solutions written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/shenril/rustlings-solutions already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+50be22964035027398754e54cd3a497efb00f83e" "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-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+50be22964035027398754e54cd3a497efb00f83e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ac4ff3bd695e0cfb298f154668382e2d35fc9dc17e2eacc5d8edd197b0da6c2a
[INFO] running `Command { std: "docker" "start" "-a" "ac4ff3bd695e0cfb298f154668382e2d35fc9dc17e2eacc5d8edd197b0da6c2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ac4ff3bd695e0cfb298f154668382e2d35fc9dc17e2eacc5d8edd197b0da6c2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac4ff3bd695e0cfb298f154668382e2d35fc9dc17e2eacc5d8edd197b0da6c2a", kill_on_drop: false }`
[INFO] [stdout] ac4ff3bd695e0cfb298f154668382e2d35fc9dc17e2eacc5d8edd197b0da6c2a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+50be22964035027398754e54cd3a497efb00f83e" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3a24fe6a4f3217bbbee4a781597586b648d482d1f35a7a04531e3b93cd4506f5
[INFO] running `Command { std: "docker" "start" "-a" "3a24fe6a4f3217bbbee4a781597586b648d482d1f35a7a04531e3b93cd4506f5", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]     Checking lazy_static v1.3.0
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling regex v1.1.6
[INFO] [stderr]     Checking unicode-width v0.1.5
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]     Checking utf8-ranges v1.0.2
[INFO] [stderr]     Checking scopeguard v1.0.0
[INFO] [stderr]     Checking smallvec v0.6.9
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling parking_lot_core v0.5.0
[INFO] [stderr]    Compiling parking_lot v0.8.0
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking lock_api v0.2.0
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking regex-syntax v0.6.6
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking lazy_static v0.2.11
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]    Compiling serde v1.0.92
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]     Checking regex-syntax v0.5.6
[INFO] [stderr]     Checking clicolors-control v1.0.0
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking same-file v1.0.4
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking lazycell v1.2.1
[INFO] [stderr]     Checking inotify v0.6.1
[INFO] [stderr]     Checking clicolors-control v0.2.0
[INFO] [stderr]     Checking walkdir v2.2.7
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking filetime v0.2.5
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking aho-corasick v0.7.3
[INFO] [stderr]     Checking aho-corasick v0.6.10
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]     Checking mio-extras v2.0.5
[INFO] [stderr]     Checking notify v4.0.12
[INFO] [stderr]     Checking console v0.7.5
[INFO] [stderr]     Checking console v0.6.2
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]     Checking indicatif v0.9.0
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]  Documenting rustlings v1.3.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 7.13s
[INFO] [stderr]    Generated /opt/rustwide/target/doc/rustlings/index.html
[INFO] running `Command { std: "docker" "inspect" "3a24fe6a4f3217bbbee4a781597586b648d482d1f35a7a04531e3b93cd4506f5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3a24fe6a4f3217bbbee4a781597586b648d482d1f35a7a04531e3b93cd4506f5", kill_on_drop: false }`
[INFO] [stdout] 3a24fe6a4f3217bbbee4a781597586b648d482d1f35a7a04531e3b93cd4506f5