[INFO] cloning repository raiker/persistent-rope
[INFO] running `"git" "clone" "--bare" "git://github.com/raiker/persistent-rope.git" "work/cache/sources/gh/raiker/persistent-rope"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/raiker/persistent-rope'...
[INFO] running `"git" "clone" "work/cache/sources/gh/raiker/persistent-rope" "work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/raiker/persistent-rope"`
[INFO] [stderr] Cloning into 'work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/raiker/persistent-rope'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/raiker/persistent-rope" "work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/raiker/persistent-rope"`
[INFO] [stderr] Cloning into 'work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/raiker/persistent-rope'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 7f638488c32998e1683a0a3ba8de4846c9a5dee7
[INFO] sha for GitHub repo raiker/persistent-rope: 7f638488c32998e1683a0a3ba8de4846c9a5dee7
[INFO] validating manifest of raiker/persistent-rope on toolchain master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of raiker/persistent-rope on toolchain try#8f81d0bf6baf07b92f1246696722485c4ca0b049
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing raiker/persistent-rope
[INFO] finished frobbing raiker/persistent-rope
[INFO] frobbed toml for raiker/persistent-rope written to work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/raiker/persistent-rope/Cargo.toml
[INFO] started frobbing raiker/persistent-rope
[INFO] finished frobbing raiker/persistent-rope
[INFO] frobbed toml for raiker/persistent-rope written to work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/raiker/persistent-rope/Cargo.toml
[INFO] crate raiker/persistent-rope already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking raiker/persistent-rope against try#8f81d0bf6baf07b92f1246696722485c4ca0b049 for pr-62008
[INFO] running `"docker" "create" "-v" "/mnt/big/ec2-user/crater/work/local/target-dirs/pr-62008/worker-3/try#8f81d0bf6baf07b92f1246696722485c4ca0b049:/opt/crater/target:rw,Z" "-v" "/mnt/big/ec2-user/crater/work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/raiker/persistent-rope:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] cc003dd9db0cb21966ab142efd53f5da96a1bda7a6ea714f224756c599b1d899
[INFO] running `"docker" "start" "-a" "cc003dd9db0cb21966ab142efd53f5da96a1bda7a6ea714f224756c599b1d899"`
[INFO] [stderr] Checking persistent-rope v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `parent`
[INFO] [stderr] --> src/main.rs:141:69
[INFO] [stderr] |
[INFO] [stderr] 141 | fn rec_insert(key: K, val: V, current: &Rc