[INFO] updating cached repository christiansakai/linked_list_rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/christiansakai/linked_list_rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/christiansakai/linked_list_rust" "work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/christiansakai/linked_list_rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/christiansakai/linked_list_rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/christiansakai/linked_list_rust" "work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/christiansakai/linked_list_rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/christiansakai/linked_list_rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b59f6d038c7a3a9c7cfb4a83a0103de5a7b175ce
[INFO] sha for GitHub repo christiansakai/linked_list_rust: b59f6d038c7a3a9c7cfb4a83a0103de5a7b175ce
[INFO] validating manifest of christiansakai/linked_list_rust on toolchain master#5f9c0448dde167128d668da4555879f64e56af1d
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of christiansakai/linked_list_rust on toolchain try#8ec8125bea94852768b56958f05da47666c21ab0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing christiansakai/linked_list_rust
[INFO] finished frobbing christiansakai/linked_list_rust
[INFO] frobbed toml for christiansakai/linked_list_rust written to work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/christiansakai/linked_list_rust/Cargo.toml
[INFO] started frobbing christiansakai/linked_list_rust
[INFO] finished frobbing christiansakai/linked_list_rust
[INFO] frobbed toml for christiansakai/linked_list_rust written to work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/christiansakai/linked_list_rust/Cargo.toml
[INFO] crate christiansakai/linked_list_rust already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking christiansakai/linked_list_rust against master#5f9c0448dde167128d668da4555879f64e56af1d for pr-62133
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-62133/worker-1/master#5f9c0448dde167128d668da4555879f64e56af1d:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/christiansakai/linked_list_rust:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/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" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] b77e7f4fcc0b16ead18f2c71ba5ce550a353460f4ef1d8db34081dd31dc92abe
[INFO] running `"docker" "start" "-a" "b77e7f4fcc0b16ead18f2c71ba5ce550a353460f4ef1d8db34081dd31dc92abe"`
[INFO] [stderr]     Checking linked_list_rust v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/first.rs:75:9
[INFO] [stderr]    |
[INFO] [stderr] 75 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `elem`
[INFO] [stderr]   --> src/fourth.rs:51:33
[INFO] [stderr]    |
[INFO] [stderr] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stderr]    |                                 ^^^^ help: consider prefixing with an underscore: `_elem`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `elem`
[INFO] [stderr]   --> src/fourth.rs:51:33
[INFO] [stderr]    |
[INFO] [stderr] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stderr]    |                                 ^^^^ help: consider prefixing with an underscore: `_elem`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.85s
[INFO] running `"docker" "inspect" "b77e7f4fcc0b16ead18f2c71ba5ce550a353460f4ef1d8db34081dd31dc92abe"`
[INFO] running `"docker" "rm" "-f" "b77e7f4fcc0b16ead18f2c71ba5ce550a353460f4ef1d8db34081dd31dc92abe"`
[INFO] [stdout] b77e7f4fcc0b16ead18f2c71ba5ce550a353460f4ef1d8db34081dd31dc92abe