[INFO] updating cached repository amitdash291/rust_lifetimes
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/amitdash291/rust_lifetimes
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/amitdash291/rust_lifetimes" "work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/amitdash291/rust_lifetimes"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/amitdash291/rust_lifetimes'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/amitdash291/rust_lifetimes" "work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/amitdash291/rust_lifetimes"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/amitdash291/rust_lifetimes'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1de31b9f2321d84ba42e1c3319e2142917794fe9
[INFO] sha for GitHub repo amitdash291/rust_lifetimes: 1de31b9f2321d84ba42e1c3319e2142917794fe9
[INFO] validating manifest of amitdash291/rust_lifetimes on toolchain master#60960a260f7b5c695fd0717311d72ce62dd4eb43
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of amitdash291/rust_lifetimes on toolchain try#266783e4e09e4e9d5307c1c8e695659c58bbcac7
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing amitdash291/rust_lifetimes
[INFO] finished frobbing amitdash291/rust_lifetimes
[INFO] frobbed toml for amitdash291/rust_lifetimes written to work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/amitdash291/rust_lifetimes/Cargo.toml
[INFO] started frobbing amitdash291/rust_lifetimes
[INFO] finished frobbing amitdash291/rust_lifetimes
[INFO] frobbed toml for amitdash291/rust_lifetimes written to work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/amitdash291/rust_lifetimes/Cargo.toml
[INFO] crate amitdash291/rust_lifetimes already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking amitdash291/rust_lifetimes against try#266783e4e09e4e9d5307c1c8e695659c58bbcac7 for pr-63376
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-63376/worker-3/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/amitdash291/rust_lifetimes:/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" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 2b8a987ae73be48d3fa97328c4a99b894fd778bd5e8445d4e74df898d02eff9e
[INFO] running `"docker" "start" "-a" "2b8a987ae73be48d3fa97328c4a99b894fd778bd5e8445d4e74df898d02eff9e"`
[INFO] [stderr]     Checking lifetime_demo v0.1.0 (/opt/crater/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: consider prefixing 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: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vec1`
[INFO] [stderr]   --> src/main.rs:37:13
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut vec1: Vec<i32> = Vec::new();
[INFO] [stderr]    |             ^^^^ help: consider prefixing 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:34:1
[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:40:1
[INFO] [stderr]    |
[INFO] [stderr] 40 | fn copy_vec(from: &Vec<i32>, to: &mut Vec<i32>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[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: consider prefixing 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: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `vec1`
[INFO] [stderr]   --> src/main.rs:37:13
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut vec1: Vec<i32> = Vec::new();
[INFO] [stderr]    |             ^^^^ help: consider prefixing 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:34:1
[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:40:1
[INFO] [stderr]    |
[INFO] [stderr] 40 | fn copy_vec(from: &Vec<i32>, to: &mut Vec<i32>) {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.32s
[INFO] running `"docker" "inspect" "2b8a987ae73be48d3fa97328c4a99b894fd778bd5e8445d4e74df898d02eff9e"`
[INFO] running `"docker" "rm" "-f" "2b8a987ae73be48d3fa97328c4a99b894fd778bd5e8445d4e74df898d02eff9e"`
[INFO] [stdout] 2b8a987ae73be48d3fa97328c4a99b894fd778bd5e8445d4e74df898d02eff9e