[INFO] updating cached repository https://github.com/amitdash291/rust_lifetimes
[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] 1de31b9f2321d84ba42e1c3319e2142917794fe9
[INFO] checking amitdash291/rust_lifetimes against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Famitdash291%2Frust_lifetimes" "/workspace/builds/worker-13/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-13/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/amitdash291/rust_lifetimes 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/amitdash291/rust_lifetimes
[INFO] finished tweaking git repo https://github.com/amitdash291/rust_lifetimes
[INFO] tweaked toml for git repo https://github.com/amitdash291/rust_lifetimes written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate git repo https://github.com/amitdash291/rust_lifetimes already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] [stdout] 2ab1e909f51cb41cd2fda838f1bb20748829785a176aaa7dfcc4a9b1aba30366
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "2ab1e909f51cb41cd2fda838f1bb20748829785a176aaa7dfcc4a9b1aba30366"`
[INFO] [stderr]     Checking lifetime_demo v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable `result_ref` is assigned to, but never used
[INFO] [stderr]  --> src/main.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let result_ref;
[INFO] [stderr]   |         ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr]   = note: consider using `_result_ref` instead
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `result_ref` is never read
[INFO] [stderr]  --> src/main.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     result_ref = which_is_greater(&a, &b)
[INFO] [stderr]   |     ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]   = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]   --> src/main.rs:25:29
[INFO] [stderr]    |
[INFO] [stderr] 25 | fn which_is_greater<'a, 'b>(a: &'a i32, b: &'b i32) -> &'b i32 {
[INFO] [stderr]    |                             ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]   --> src/main.rs:25:41
[INFO] [stderr]    |
[INFO] [stderr] 25 | fn which_is_greater<'a, 'b>(a: &'a i32, b: &'b i32) -> &'b i32 {
[INFO] [stderr]    |                                         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vec1`
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut vec1: Vec<i32> = Vec::new();
[INFO] [stderr]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_vec1`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut vec1: Vec<i32> = Vec::new();
[INFO] [stderr]    |         ----^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_mut_ref`
[INFO] [stderr]   --> src/main.rs:34:4
[INFO] [stderr]    |
[INFO] [stderr] 34 | fn test_mut_ref() {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `copy_vec`
[INFO] [stderr]   --> src/main.rs:40:4
[INFO] [stderr]    |
[INFO] [stderr] 40 | fn copy_vec(from: &Vec<i32>, to: &mut Vec<i32>) {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 8 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: variable `result_ref` is assigned to, but never used
[INFO] [stderr]  --> src/main.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let result_ref;
[INFO] [stderr]   |         ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr]   = note: consider using `_result_ref` instead
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `result_ref` is never read
[INFO] [stderr]  --> src/main.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     result_ref = which_is_greater(&a, &b)
[INFO] [stderr]   |     ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]   = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]   --> src/main.rs:25:29
[INFO] [stderr]    |
[INFO] [stderr] 25 | fn which_is_greater<'a, 'b>(a: &'a i32, b: &'b i32) -> &'b i32 {
[INFO] [stderr]    |                             ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]   --> src/main.rs:25:41
[INFO] [stderr]    |
[INFO] [stderr] 25 | fn which_is_greater<'a, 'b>(a: &'a i32, b: &'b i32) -> &'b i32 {
[INFO] [stderr]    |                                         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vec1`
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut vec1: Vec<i32> = Vec::new();
[INFO] [stderr]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_vec1`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut vec1: Vec<i32> = Vec::new();
[INFO] [stderr]    |         ----^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `test_mut_ref`
[INFO] [stderr]   --> src/main.rs:34:4
[INFO] [stderr]    |
[INFO] [stderr] 34 | fn test_mut_ref() {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `copy_vec`
[INFO] [stderr]   --> src/main.rs:40:4
[INFO] [stderr]    |
[INFO] [stderr] 40 | fn copy_vec(from: &Vec<i32>, to: &mut Vec<i32>) {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 8 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.47s
[INFO] running `"docker" "inspect" "2ab1e909f51cb41cd2fda838f1bb20748829785a176aaa7dfcc4a9b1aba30366"`
[INFO] running `"docker" "rm" "-f" "2ab1e909f51cb41cd2fda838f1bb20748829785a176aaa7dfcc4a9b1aba30366"`
[INFO] [stdout] 2ab1e909f51cb41cd2fda838f1bb20748829785a176aaa7dfcc4a9b1aba30366