[INFO] cloning repository https://github.com/vrbala/rust_solutions
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/vrbala/rust_solutions" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrbala%2Frust_solutions", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvrbala%2Frust_solutions'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 414b3f2a1c68b9f17cf092a2a6507414655daede
[INFO] documenting vrbala/rust_solutions 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%2Fvrbala%2Frust_solutions" "/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/vrbala/rust_solutions 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/vrbala/rust_solutions
[INFO] finished tweaking git repo https://github.com/vrbala/rust_solutions
[INFO] tweaked toml for git repo https://github.com/vrbala/rust_solutions written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/vrbala/rust_solutions 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] error: the lock file /workspace/builds/worker-7/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--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" "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] c8467b414e50e7547a179fdcc10ef1875b835fc0cbc1763313d269cc5e61828e
[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" "c8467b414e50e7547a179fdcc10ef1875b835fc0cbc1763313d269cc5e61828e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c8467b414e50e7547a179fdcc10ef1875b835fc0cbc1763313d269cc5e61828e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c8467b414e50e7547a179fdcc10ef1875b835fc0cbc1763313d269cc5e61828e", kill_on_drop: false }`
[INFO] [stdout] c8467b414e50e7547a179fdcc10ef1875b835fc0cbc1763313d269cc5e61828e
[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" "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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 363d13e149bbf553ad9c5babb4d58114fd2fcf6517060c310883da1625948d11
[INFO] running `Command { std: "docker" "start" "-a" "363d13e149bbf553ad9c5babb4d58114fd2fcf6517060c310883da1625948d11", kill_on_drop: false }`
[INFO] [stderr]     Checking instant v0.1.6
[INFO] [stderr]     Checking lazycell v1.3.0
[INFO] [stderr]     Checking lock_api v0.4.1
[INFO] [stderr]     Checking termios v0.3.2
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking terminal_size v0.1.13
[INFO] [stderr]     Checking filetime v0.2.12
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking parking_lot_core v0.8.0
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking console v0.12.0
[INFO] [stderr]     Checking parking_lot v0.11.0
[INFO] [stderr]     Checking notify v4.0.15
[INFO] [stderr]     Checking console v0.7.7
[INFO] [stderr]     Checking indicatif v0.10.3
[INFO] [stderr]  Documenting rustlings v3.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.75s
[INFO] running `Command { std: "docker" "inspect" "363d13e149bbf553ad9c5babb4d58114fd2fcf6517060c310883da1625948d11", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "363d13e149bbf553ad9c5babb4d58114fd2fcf6517060c310883da1625948d11", kill_on_drop: false }`
[INFO] [stdout] 363d13e149bbf553ad9c5babb4d58114fd2fcf6517060c310883da1625948d11