[INFO] cloning repository https://github.com/megalypse/rust_collections_exercise
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/megalypse/rust_collections_exercise" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmegalypse%2Frust_collections_exercise", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmegalypse%2Frust_collections_exercise'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c9af602a140cb4262ddb1dbd3792be6c999b669d
[INFO] checking megalypse/rust_collections_exercise against master#d3dd34a1d4a7e25a92a0d65994bb01a5d17c59ee for pr-127481-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmegalypse%2Frust_collections_exercise" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/megalypse/rust_collections_exercise on toolchain d3dd34a1d4a7e25a92a0d65994bb01a5d17c59ee
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d3dd34a1d4a7e25a92a0d65994bb01a5d17c59ee" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/megalypse/rust_collections_exercise
[INFO] finished tweaking git repo https://github.com/megalypse/rust_collections_exercise
[INFO] tweaked toml for git repo https://github.com/megalypse/rust_collections_exercise written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/megalypse/rust_collections_exercise 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" "+d3dd34a1d4a7e25a92a0d65994bb01a5d17c59ee" "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 megalypse/rust_collections_exercise against try#3d1ad905b56a11961be37df7dc5e56be58204dd8 for pr-127481-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmegalypse%2Frust_collections_exercise" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/megalypse/rust_collections_exercise on toolchain 3d1ad905b56a11961be37df7dc5e56be58204dd8
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3d1ad905b56a11961be37df7dc5e56be58204dd8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/megalypse/rust_collections_exercise
[INFO] finished tweaking git repo https://github.com/megalypse/rust_collections_exercise
[INFO] tweaked toml for git repo https://github.com/megalypse/rust_collections_exercise written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/megalypse/rust_collections_exercise 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" "+3d1ad905b56a11961be37df7dc5e56be58204dd8" "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-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:dff56e7819e73ed36160586b3445e93eb0be776c16704aeeded9c3fb668b2384" "/opt/rustwide/cargo-home/bin/cargo" "+3d1ad905b56a11961be37df7dc5e56be58204dd8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7203c3ecbfb7ef63375cd02fdbbc1249249e06e638ecb01dace3361d012b9bbd
[INFO] running `Command { std: "docker" "start" "-a" "7203c3ecbfb7ef63375cd02fdbbc1249249e06e638ecb01dace3361d012b9bbd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7203c3ecbfb7ef63375cd02fdbbc1249249e06e638ecb01dace3361d012b9bbd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7203c3ecbfb7ef63375cd02fdbbc1249249e06e638ecb01dace3361d012b9bbd", kill_on_drop: false }`
[INFO] [stdout] 7203c3ecbfb7ef63375cd02fdbbc1249249e06e638ecb01dace3361d012b9bbd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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:dff56e7819e73ed36160586b3445e93eb0be776c16704aeeded9c3fb668b2384" "/opt/rustwide/cargo-home/bin/cargo" "+3d1ad905b56a11961be37df7dc5e56be58204dd8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5564bf3a9f083bf918f9e94438a0f107f9953e8464387c57a404dfe64ec6b7a9
[INFO] running `Command { std: "docker" "start" "-a" "5564bf3a9f083bf918f9e94438a0f107f9953e8464387c57a404dfe64ec6b7a9", kill_on_drop: false }`
[INFO] [stderr]     Checking ch_8_exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `res` is never read
[INFO] [stdout]  --> src/meds/median.rs:5:13
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut res = 0;
[INFO] [stdout]   |             ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `res` is never read
[INFO] [stdout]  --> src/meds/median.rs:5:13
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut res = 0;
[INFO] [stdout]   |             ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `new_word` is never read
[INFO] [stdout]  --> src/pig_latim/pig_latimner.rs:8:13
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let mut new_word = String::new();
[INFO] [stdout]   |             ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `new_word` is never read
[INFO] [stdout]  --> src/pig_latim/pig_latimner.rs:8:13
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let mut new_word = String::new();
[INFO] [stdout]   |             ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[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" "5564bf3a9f083bf918f9e94438a0f107f9953e8464387c57a404dfe64ec6b7a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5564bf3a9f083bf918f9e94438a0f107f9953e8464387c57a404dfe64ec6b7a9", kill_on_drop: false }`
[INFO] [stdout] 5564bf3a9f083bf918f9e94438a0f107f9953e8464387c57a404dfe64ec6b7a9