[INFO] cloning repository https://github.com/ForPractice57657876/R20210618
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ForPractice57657876/R20210618" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FForPractice57657876%2FR20210618", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FForPractice57657876%2FR20210618'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dde33db7fa7645a3aac9738cc63e8682233ccc2e
[INFO] building ForPractice57657876/R20210618 against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FForPractice57657876%2FR20210618" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ForPractice57657876/R20210618 on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ForPractice57657876/R20210618
[INFO] finished tweaking git repo https://github.com/ForPractice57657876/R20210618
[INFO] tweaked toml for git repo https://github.com/ForPractice57657876/R20210618 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/ForPractice57657876/R20210618 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2b682e6fa6b0108efb9c98ca3293f843161ddb9b0d2797c2f6a3b98710b156df
[INFO] running `Command { std: "docker" "start" "-a" "2b682e6fa6b0108efb9c98ca3293f843161ddb9b0d2797c2f6a3b98710b156df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2b682e6fa6b0108efb9c98ca3293f843161ddb9b0d2797c2f6a3b98710b156df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2b682e6fa6b0108efb9c98ca3293f843161ddb9b0d2797c2f6a3b98710b156df", kill_on_drop: false }`
[INFO] [stdout] 2b682e6fa6b0108efb9c98ca3293f843161ddb9b0d2797c2f6a3b98710b156df
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 98f7b54b8404b7aa798d96c5e9a27b5d7cbf77373e95dd5f842df8e5b9d1d6eb
[INFO] running `Command { std: "docker" "start" "-a" "98f7b54b8404b7aa798d96c5e9a27b5d7cbf77373e95dd5f842df8e5b9d1d6eb", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.97
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling R20210618 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `rand::Rng`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use rand::Rng;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `i1` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:40:13
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let mut i1=&  a;
[INFO] [stdout]    |             ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_i1` instead
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i2`
[INFO] [stdout]   --> src/main.rs:41:13
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let mut i2=&  a;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `i1` is never read
[INFO] [stdout]   --> src/main.rs:43:5
[INFO] [stdout]    |
[INFO] [stdout] 43 |     i1=& mut f;
[INFO] [stdout]    |     ^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:39:11
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn footwo(mut a: Rec)->i32{
[INFO] [stdout]    |           ----^
[INFO] [stdout]    |           |
[INFO] [stdout]    |           help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let mut i2=&  a;
[INFO] [stdout]    |         ----^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/main.rs:52:10
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn foo31(e:&E){
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rec` is never constructed
[INFO] [stdout]   --> src/main.rs:29:12
[INFO] [stdout]    |
[INFO] [stdout] 29 |     struct Rec {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `foo` is never used
[INFO] [stdout]   --> src/main.rs:34:12
[INFO] [stdout]    |
[INFO] [stdout] 33 |     impl Rec {
[INFO] [stdout]    |     -------- method in this implementation
[INFO] [stdout] 34 |         fn foo( self:& mut Rec){
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `footwo` is never used
[INFO] [stdout]   --> src/main.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn footwo(mut a: Rec)->i32{
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `E` is never used
[INFO] [stdout]   --> src/main.rs:48:6
[INFO] [stdout]    |
[INFO] [stdout] 48 | enum E{
[INFO] [stdout]    |      ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foo31` is never used
[INFO] [stdout]   --> src/main.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn foo31(e:&E){
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foo3` is never used
[INFO] [stdout]   --> src/main.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn foo3 (e:E)->i32{
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     io::stdin().read_line(&mut guess);
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let _ = io::stdin().read_line(&mut guess);
[INFO] [stdout]   |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused arithmetic operation that must be used
[INFO] [stdout]   --> src/main.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 |     1+1;
[INFO] [stdout]    |     ^^^ the arithmetic operation produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let _ = 1+1;
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.20s
[INFO] running `Command { std: "docker" "inspect" "98f7b54b8404b7aa798d96c5e9a27b5d7cbf77373e95dd5f842df8e5b9d1d6eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "98f7b54b8404b7aa798d96c5e9a27b5d7cbf77373e95dd5f842df8e5b9d1d6eb", kill_on_drop: false }`
[INFO] [stdout] 98f7b54b8404b7aa798d96c5e9a27b5d7cbf77373e95dd5f842df8e5b9d1d6eb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 421adf96aa009f1aa39d6b88e0c965bda4ac5061767d2e132c29b085c8f96a07
[INFO] running `Command { std: "docker" "start" "-a" "421adf96aa009f1aa39d6b88e0c965bda4ac5061767d2e132c29b085c8f96a07", kill_on_drop: false }`
[INFO] [stderr]    Compiling R20210618 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `rand::Rng`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use rand::Rng;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `i1` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:40:13
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let mut i1=&  a;
[INFO] [stdout]    |             ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_i1` instead
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i2`
[INFO] [stdout]   --> src/main.rs:41:13
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let mut i2=&  a;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `i1` is never read
[INFO] [stdout]   --> src/main.rs:43:5
[INFO] [stdout]    |
[INFO] [stdout] 43 |     i1=& mut f;
[INFO] [stdout]    |     ^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:39:11
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn footwo(mut a: Rec)->i32{
[INFO] [stdout]    |           ----^
[INFO] [stdout]    |           |
[INFO] [stdout]    |           help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let mut i2=&  a;
[INFO] [stdout]    |         ----^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/main.rs:52:10
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn foo31(e:&E){
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rec` is never constructed
[INFO] [stdout]   --> src/main.rs:29:12
[INFO] [stdout]    |
[INFO] [stdout] 29 |     struct Rec {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `foo` is never used
[INFO] [stdout]   --> src/main.rs:34:12
[INFO] [stdout]    |
[INFO] [stdout] 33 |     impl Rec {
[INFO] [stdout]    |     -------- method in this implementation
[INFO] [stdout] 34 |         fn foo( self:& mut Rec){
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `footwo` is never used
[INFO] [stdout]   --> src/main.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn footwo(mut a: Rec)->i32{
[INFO] [stdout]    |    ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `E` is never used
[INFO] [stdout]   --> src/main.rs:48:6
[INFO] [stdout]    |
[INFO] [stdout] 48 | enum E{
[INFO] [stdout]    |      ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foo31` is never used
[INFO] [stdout]   --> src/main.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn foo31(e:&E){
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foo3` is never used
[INFO] [stdout]   --> src/main.rs:57:4
[INFO] [stdout]    |
[INFO] [stdout] 57 | fn foo3 (e:E)->i32{
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     io::stdin().read_line(&mut guess);
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let _ = io::stdin().read_line(&mut guess);
[INFO] [stdout]   |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused arithmetic operation that must be used
[INFO] [stdout]   --> src/main.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 |     1+1;
[INFO] [stdout]    |     ^^^ the arithmetic operation produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let _ = 1+1;
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.16s
[INFO] running `Command { std: "docker" "inspect" "421adf96aa009f1aa39d6b88e0c965bda4ac5061767d2e132c29b085c8f96a07", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "421adf96aa009f1aa39d6b88e0c965bda4ac5061767d2e132c29b085c8f96a07", kill_on_drop: false }`
[INFO] [stdout] 421adf96aa009f1aa39d6b88e0c965bda4ac5061767d2e132c29b085c8f96a07