[INFO] cloning repository https://github.com/Howe829/flow_control
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Howe829/flow_control" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHowe829%2Fflow_control", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHowe829%2Fflow_control'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 04f6ba5bed9ec043d8cd33a43c8b4755ac5f8ddb
[INFO] checking Howe829/flow_control against master#30f74ff0dc4d66debc8b50724c446f817e5f75f4 for pr-121848-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHowe829%2Fflow_control" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Howe829/flow_control on toolchain 30f74ff0dc4d66debc8b50724c446f817e5f75f4
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Howe829/flow_control
[INFO] finished tweaking git repo https://github.com/Howe829/flow_control
[INFO] tweaked toml for git repo https://github.com/Howe829/flow_control written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Howe829/flow_control 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" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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] checking Howe829/flow_control against try#72eda894eb3548c7ba774079ce0afab42958d4ee for pr-121848-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHowe829%2Fflow_control" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Howe829/flow_control on toolchain 72eda894eb3548c7ba774079ce0afab42958d4ee
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Howe829/flow_control
[INFO] finished tweaking git repo https://github.com/Howe829/flow_control
[INFO] tweaked toml for git repo https://github.com/Howe829/flow_control written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Howe829/flow_control 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" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a14b8aad7b7cfa006d5d0e5d0b34907b663336c32c411a1e92fa1b94611a128d
[INFO] running `Command { std: "docker" "start" "-a" "a14b8aad7b7cfa006d5d0e5d0b34907b663336c32c411a1e92fa1b94611a128d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a14b8aad7b7cfa006d5d0e5d0b34907b663336c32c411a1e92fa1b94611a128d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a14b8aad7b7cfa006d5d0e5d0b34907b663336c32c411a1e92fa1b94611a128d", kill_on_drop: false }`
[INFO] [stdout] a14b8aad7b7cfa006d5d0e5d0b34907b663336c32c411a1e92fa1b94611a128d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6b4bb1fd1d5d3a9d196dc489e048719f580003483bb313e7690e8ca9cde09352
[INFO] running `Command { std: "docker" "start" "-a" "6b4bb1fd1d5d3a9d196dc489e048719f580003483bb313e7690e8ca9cde09352", kill_on_drop: false }`
[INFO] [stderr]     Checking flow_control v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     for i in 2..n {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     for i in 2..n {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `loop_examples` is never used
[INFO] [stdout]   --> src/main.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn loop_examples() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `loop_examples` is never used
[INFO] [stdout]   --> src/main.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn loop_examples() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.06s
[INFO] running `Command { std: "docker" "inspect" "6b4bb1fd1d5d3a9d196dc489e048719f580003483bb313e7690e8ca9cde09352", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b4bb1fd1d5d3a9d196dc489e048719f580003483bb313e7690e8ca9cde09352", kill_on_drop: false }`
[INFO] [stdout] 6b4bb1fd1d5d3a9d196dc489e048719f580003483bb313e7690e8ca9cde09352