[INFO] updating cached repository https://github.com/VitalyAnkh/learn_error_handling
[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] a9cf67b08bbfba5b416953d982e1a8eada6ad2f8
[INFO] checking VitalyAnkh/learn_error_handling against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVitalyAnkh%2Flearn_error_handling" "/workspace/builds/worker-1/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/VitalyAnkh/learn_error_handling 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/VitalyAnkh/learn_error_handling
[INFO] finished tweaking git repo https://github.com/VitalyAnkh/learn_error_handling
[INFO] tweaked toml for git repo https://github.com/VitalyAnkh/learn_error_handling written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/VitalyAnkh/learn_error_handling 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] 143e9da422690df718cd568365961ebca6435e48bc40a84fa20021e765f46cc2
[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" "143e9da422690df718cd568365961ebca6435e48bc40a84fa20021e765f46cc2"`
[INFO] [stderr]     Checking learn_error_handling v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused imports: `Cons`, `Nil`
[INFO] [stderr]  --> src/smart_pointer/rc.rs:7:18
[INFO] [stderr]   |
[INFO] [stderr] 7 | use self::List::{Cons,Nil};
[INFO] [stderr]   |                  ^^^^ ^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Guess`
[INFO] [stderr]  --> src/read/mod.rs:5:8
[INFO] [stderr]   |
[INFO] [stderr] 5 | struct Guess {
[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/read/mod.rs:10:5
[INFO] [stderr]    |
[INFO] [stderr] 10 |     fn new(value: u32) -> Guess {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `List`
[INFO] [stderr]  --> src/smart_pointer/rc.rs:1:6
[INFO] [stderr]   |
[INFO] [stderr] 1 | enum List{
[INFO] [stderr]   |      ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: comparison is useless due to type limits
[INFO] [stderr]   --> src/read/mod.rs:11:12
[INFO] [stderr]    |
[INFO] [stderr] 11 |         if value < 0 || value > 100 {
[INFO] [stderr]    |            ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_comparisons)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]   --> src/smart_pointer/rc.rs:12:9
[INFO] [stderr]    |
[INFO] [stderr] 12 |     let b = Cons(2,Rc::clone(&a));
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]  --> src/smart_pointer/ref_cell.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let mut y =&a;
[INFO] [stderr]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> src/smart_pointer/ref_cell.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let mut y =&a;
[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: field is never read: `value`
[INFO] [stderr]  --> src/read/mod.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     value: u32
[INFO] [stderr]   |     ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: comparison is useless due to type limits
[INFO] [stderr]   --> src/read/mod.rs:11:12
[INFO] [stderr]    |
[INFO] [stderr] 11 |         if value < 0 || value > 100 {
[INFO] [stderr]    |            ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_comparisons)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> tests/integration_test.rs:11:9
[INFO] [stderr]    |
[INFO] [stderr] 11 |     let y =&a;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `it_add_two`
[INFO] [stderr]  --> tests/integration_test.rs:5:4
[INFO] [stderr]   |
[INFO] [stderr] 5 | fn it_add_two(){
[INFO] [stderr]   |    ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `check_borrow_rules`
[INFO] [stderr]  --> tests/integration_test.rs:9:4
[INFO] [stderr]   |
[INFO] [stderr] 9 | fn check_borrow_rules(){
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 3 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.89s
[INFO] running `"docker" "inspect" "143e9da422690df718cd568365961ebca6435e48bc40a84fa20021e765f46cc2"`
[INFO] running `"docker" "rm" "-f" "143e9da422690df718cd568365961ebca6435e48bc40a84fa20021e765f46cc2"`
[INFO] [stdout] 143e9da422690df718cd568365961ebca6435e48bc40a84fa20021e765f46cc2