[INFO] cloning repository https://github.com/nikomatsakis/skill-tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nikomatsakis/skill-tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnikomatsakis%2Fskill-tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnikomatsakis%2Fskill-tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d486693b750bacd7fa58ad1743e2f8c6bcba6cee
[INFO] checking nikomatsakis/skill-tree against master#d62d3f7fa9a91d933213cc10e20e740608983f64 for pr-77015
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnikomatsakis%2Fskill-tree" "/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/nikomatsakis/skill-tree on toolchain d62d3f7fa9a91d933213cc10e20e740608983f64
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/nikomatsakis/skill-tree
[INFO] removed workspace from git repo https://github.com/nikomatsakis/skill-tree
[INFO] finished tweaking git repo https://github.com/nikomatsakis/skill-tree
[INFO] tweaked toml for git repo https://github.com/nikomatsakis/skill-tree written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/nikomatsakis/skill-tree already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "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[INFO] the lockfile is outdated, regenerating it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" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "fetch" "--locked" "--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-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" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0964de54193103edd9808f7010854c9fc2553f3fee69bbd2d27ead47aaf0d8f0
[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" "0964de54193103edd9808f7010854c9fc2553f3fee69bbd2d27ead47aaf0d8f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0964de54193103edd9808f7010854c9fc2553f3fee69bbd2d27ead47aaf0d8f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0964de54193103edd9808f7010854c9fc2553f3fee69bbd2d27ead47aaf0d8f0", kill_on_drop: false }`
[INFO] [stdout] 0964de54193103edd9808f7010854c9fc2553f3fee69bbd2d27ead47aaf0d8f0
[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" "RUSTFLAGS=--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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 644473dbb6f77ee1023e5f2928b37467cdb3760510f290e063efa5df2a942396
[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" "644473dbb6f77ee1023e5f2928b37467cdb3760510f290e063efa5df2a942396", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.42
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling unicode-segmentation v1.6.0
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking svg v0.5.12
[INFO] [stderr]     Checking htmlescape v0.3.1
[INFO] [stderr]     Checking serde v1.0.116
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]     Checking toml v0.5.6
[INFO] [stderr]    Compiling structopt-derive v0.4.11
[INFO] [stderr]    Compiling fehler-macros v1.0.0
[INFO] [stderr]    Compiling serde_derive v1.0.116
[INFO] [stderr]     Checking structopt v0.3.18
[INFO] [stderr]     Checking fehler v1.0.0
[INFO] [stderr]     Checking skill-tree v2.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 47.07s
[INFO] running `Command { std: "docker" "inspect" "644473dbb6f77ee1023e5f2928b37467cdb3760510f290e063efa5df2a942396", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "644473dbb6f77ee1023e5f2928b37467cdb3760510f290e063efa5df2a942396", kill_on_drop: false }`
[INFO] [stdout] 644473dbb6f77ee1023e5f2928b37467cdb3760510f290e063efa5df2a942396