[INFO] updating cached repository https://github.com/shanemikel/rust-hello
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d473b3db08dbfe0ed83f428a13e337b242c04ce5
[INFO] checking shanemikel/rust-hello against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshanemikel%2Frust-hello" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/shanemikel/rust-hello on toolchain e4dba30b9b475d8750370c4dfb49b6541990904d
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/shanemikel/rust-hello
[INFO] finished tweaking git repo https://github.com/shanemikel/rust-hello
[INFO] tweaked toml for git repo https://github.com/shanemikel/rust-hello written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/shanemikel/rust-hello already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 6953f0853b12e4c7aefeb5b2ef12b651410f005ba2009341f740a0d39171bb15
[INFO] running `"docker" "start" "-a" "6953f0853b12e4c7aefeb5b2ef12b651410f005ba2009341f740a0d39171bb15"`
[INFO] [stderr]     Checking rust-hello v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `std::cell::RefCell`
[INFO] [stderr]  --> src/main.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |     use std::cell::RefCell;
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Mutex`
[INFO] [stderr]  --> src/main.rs:9:26
[INFO] [stderr]   |
[INFO] [stderr] 9 |     use std::sync::{Arc, Mutex, RwLock};
[INFO] [stderr]   |                          ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::cell::RefCell`
[INFO] [stderr]  --> src/main.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |     use std::cell::RefCell;
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Mutex`
[INFO] [stderr]  --> src/main.rs:9:26
[INFO] [stderr]   |
[INFO] [stderr] 9 |     use std::sync::{Arc, Mutex, RwLock};
[INFO] [stderr]   |                          ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `data`
[INFO] [stderr]   --> src/main.rs:25:17
[INFO] [stderr]    |
[INFO] [stderr] 25 |             let data = data.read().unwrap();
[INFO] [stderr]    |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_data`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `data`
[INFO] [stderr]   --> src/main.rs:25:17
[INFO] [stderr]    |
[INFO] [stderr] 25 |             let data = data.read().unwrap();
[INFO] [stderr]    |                 ^^^^ help: if this is intentional, prefix it with an underscore: `_data`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Cons`
[INFO] [stderr]  --> src/list.rs:4:5
[INFO] [stderr]   |
[INFO] [stderr] 4 |     Cons(T, Box<List<T>>),
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Nil`
[INFO] [stderr]  --> src/list.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 |     Nil,
[INFO] [stderr]   |     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]  --> src/list.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     pub fn new() -> List<T> { List::Nil }
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `cons`
[INFO] [stderr]   --> src/list.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     pub fn cons(self, x: T) -> List<T> { List::Cons(x, Box::new(self)) }
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/list.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     pub fn head(self) -> Option<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `tail`
[INFO] [stderr]   --> src/list.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     pub fn tail(&self) -> Option<&List<T>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head_ref`
[INFO] [stderr]   --> src/list.rs:29:5
[INFO] [stderr]    |
[INFO] [stderr] 29 |     pub fn head_ref(&self) -> Option<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant item is never used: `N`
[INFO] [stderr]   --> src/main.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     const N: usize = 10;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_list`
[INFO] [stderr]   --> src/main.rs:39:4
[INFO] [stderr]    |
[INFO] [stderr] 39 | fn test_list() {
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Cons`
[INFO] [stderr]  --> src/list.rs:4:5
[INFO] [stderr]   |
[INFO] [stderr] 4 |     Cons(T, Box<List<T>>),
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Nil`
[INFO] [stderr]  --> src/list.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 |     Nil,
[INFO] [stderr]   |     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]  --> src/list.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     pub fn new() -> List<T> { List::Nil }
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `cons`
[INFO] [stderr]   --> src/list.rs:11:5
[INFO] [stderr]    |
[INFO] [stderr] 11 |     pub fn cons(self, x: T) -> List<T> { List::Cons(x, Box::new(self)) }
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head`
[INFO] [stderr]   --> src/list.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     pub fn head(self) -> Option<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `tail`
[INFO] [stderr]   --> src/list.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     pub fn tail(&self) -> Option<&List<T>> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `head_ref`
[INFO] [stderr]   --> src/list.rs:29:5
[INFO] [stderr]    |
[INFO] [stderr] 29 |     pub fn head_ref(&self) -> Option<T> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant item is never used: `N`
[INFO] [stderr]   --> src/main.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     const N: usize = 10;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_list`
[INFO] [stderr]   --> src/main.rs:39:4
[INFO] [stderr]    |
[INFO] [stderr] 39 | fn test_list() {
[INFO] [stderr]    |    ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 12 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: 12 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.94s
[INFO] running `"docker" "inspect" "6953f0853b12e4c7aefeb5b2ef12b651410f005ba2009341f740a0d39171bb15"`
[INFO] running `"docker" "rm" "-f" "6953f0853b12e4c7aefeb5b2ef12b651410f005ba2009341f740a0d39171bb15"`
[INFO] [stdout] 6953f0853b12e4c7aefeb5b2ef12b651410f005ba2009341f740a0d39171bb15