[INFO] cloning repository https://github.com/raiker/persistent-rope
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/raiker/persistent-rope" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fraiker%2Fpersistent-rope", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fraiker%2Fpersistent-rope'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7f638488c32998e1683a0a3ba8de4846c9a5dee7
[INFO] checking raiker/persistent-rope against master#7b3a7819371cef92a187e9bac8f7810ccde15216 for pr-74846
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fraiker%2Fpersistent-rope" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/raiker/persistent-rope on toolchain 7b3a7819371cef92a187e9bac8f7810ccde15216
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/raiker/persistent-rope
[INFO] finished tweaking git repo https://github.com/raiker/persistent-rope
[INFO] tweaked toml for git repo https://github.com/raiker/persistent-rope written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/raiker/persistent-rope already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8928560bc5a39847cbdddf1fe44978973406734c0403be86797bf148ab9d957c
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "8928560bc5a39847cbdddf1fe44978973406734c0403be86797bf148ab9d957c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8928560bc5a39847cbdddf1fe44978973406734c0403be86797bf148ab9d957c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8928560bc5a39847cbdddf1fe44978973406734c0403be86797bf148ab9d957c", kill_on_drop: false }`
[INFO] [stdout] 8928560bc5a39847cbdddf1fe44978973406734c0403be86797bf148ab9d957c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] e6915d16c7942d9e47629c5bde76bfe1b66e59c0dc3ec670d28c598f8f6b2206
[INFO] running `Command { std: "docker" "start" "-a" "e6915d16c7942d9e47629c5bde76bfe1b66e59c0dc3ec670d28c598f8f6b2206", kill_on_drop: false }`
[INFO] [stderr]     Checking persistent-rope v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `parent`
[INFO] [stdout]    --> src/main.rs:141:69
[INFO] [stdout]     |
[INFO] [stdout] 141 | ...c<Option<TreeNode<K,V>>>, parent: Option<&Rc<Option<TreeNode<K,V>>>>) -> InsertionResultRecursion<K,V>{
[INFO] [stdout]     |                                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_parent`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `RcSliceableString`
[INFO] [stdout]  --> src/rcstr.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct RcSliceableString {
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/rcstr.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     pub fn new(s: String) -> RcSliceableString {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `slice`
[INFO] [stdout]   --> src/rcstr.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     pub fn slice(&self, start: usize, len: usize) -> RcSliceableString {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `as_str`
[INFO] [stdout]   --> src/rcstr.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     pub fn as_str(&self) -> &str {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `parent`
[INFO] [stdout]    --> src/main.rs:141:69
[INFO] [stdout]     |
[INFO] [stdout] 141 | ...c<Option<TreeNode<K,V>>>, parent: Option<&Rc<Option<TreeNode<K,V>>>>) -> InsertionResultRecursion<K,V>{
[INFO] [stdout]     |                                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_parent`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `Command { std: "docker" "inspect" "e6915d16c7942d9e47629c5bde76bfe1b66e59c0dc3ec670d28c598f8f6b2206", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e6915d16c7942d9e47629c5bde76bfe1b66e59c0dc3ec670d28c598f8f6b2206", kill_on_drop: false }`
[INFO] [stdout] e6915d16c7942d9e47629c5bde76bfe1b66e59c0dc3ec670d28c598f8f6b2206