[INFO] updating cached repository raiker/persistent-rope
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/raiker/persistent-rope
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/raiker/persistent-rope" "work/ex/pr-62507/sources/master#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7/gh/raiker/persistent-rope"`
[INFO] [stderr] Cloning into 'work/ex/pr-62507/sources/master#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7/gh/raiker/persistent-rope'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/raiker/persistent-rope" "work/ex/pr-62507/sources/try#18481b65f318e0b4b20c0fc61340054701719d6c/gh/raiker/persistent-rope"`
[INFO] [stderr] Cloning into 'work/ex/pr-62507/sources/try#18481b65f318e0b4b20c0fc61340054701719d6c/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#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+78ca1bda3522b14bc0336bc01dd1d49fdba2cda7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of raiker/persistent-rope on toolchain try#18481b65f318e0b4b20c0fc61340054701719d6c
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+18481b65f318e0b4b20c0fc61340054701719d6c-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-62507/sources/master#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7/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-62507/sources/try#18481b65f318e0b4b20c0fc61340054701719d6c/gh/raiker/persistent-rope/Cargo.toml
[INFO] crate raiker/persistent-rope already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+78ca1bda3522b14bc0336bc01dd1d49fdba2cda7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+18481b65f318e0b4b20c0fc61340054701719d6c-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking raiker/persistent-rope against master#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7 for pr-62507
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-62507/worker-3/master#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-62507/sources/master#78ca1bda3522b14bc0336bc01dd1d49fdba2cda7/gh/raiker/persistent-rope:/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" "+78ca1bda3522b14bc0336bc01dd1d49fdba2cda7-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 9cb13af60e10f3b7361eabb6e04ce58ca0d8abbb3ba0636cc4743a652768dac6
[INFO] running `"docker" "start" "-a" "9cb13af60e10f3b7361eabb6e04ce58ca0d8abbb3ba0636cc4743a652768dac6"`
[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<Option<TreeNode<K,V>>>, parent: Option<&Rc<Option<TreeNode<K,V>>>>) -> InsertionResultRecursion<K,V>{
[INFO] [stderr]     |                                                                        ^^^^^^ help: consider prefixing with an underscore: `_parent`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `RcSliceableString`
[INFO] [stderr]  --> src/rcstr.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct RcSliceableString {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/rcstr.rs:10:2
[INFO] [stderr]    |
[INFO] [stderr] 10 |     pub fn new(s: String) -> RcSliceableString {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `slice`
[INFO] [stderr]   --> src/rcstr.rs:19:2
[INFO] [stderr]    |
[INFO] [stderr] 19 |     pub fn slice(&self, start: usize, len: usize) -> RcSliceableString {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `as_str`
[INFO] [stderr]   --> src/rcstr.rs:34:2
[INFO] [stderr]    |
[INFO] [stderr] 34 |     pub fn as_str(&self) -> &str {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[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<Option<TreeNode<K,V>>>, parent: Option<&Rc<Option<TreeNode<K,V>>>>) -> InsertionResultRecursion<K,V>{
[INFO] [stderr]     |                                                                        ^^^^^^ help: consider prefixing with an underscore: `_parent`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.18s
[INFO] running `"docker" "inspect" "9cb13af60e10f3b7361eabb6e04ce58ca0d8abbb3ba0636cc4743a652768dac6"`
[INFO] running `"docker" "rm" "-f" "9cb13af60e10f3b7361eabb6e04ce58ca0d8abbb3ba0636cc4743a652768dac6"`
[INFO] [stdout] 9cb13af60e10f3b7361eabb6e04ce58ca0d8abbb3ba0636cc4743a652768dac6