[INFO] cloning repository https://github.com/TwistyShakity/rust_playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/TwistyShakity/rust_playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FTwistyShakity%2Frust_playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FTwistyShakity%2Frust_playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cf2472fa51af98a6378e5ee6cf59c9eb162d7d58
[INFO] checking TwistyShakity/rust_playground against try#f70ee28831acc074c109afab32d287057c3eca46 for pr-149389
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FTwistyShakity%2Frust_playground" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/TwistyShakity/rust_playground
[INFO] finished tweaking git repo https://github.com/TwistyShakity/rust_playground
[INFO] tweaked toml for git repo https://github.com/TwistyShakity/rust_playground written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/TwistyShakity/rust_playground on toolchain f70ee28831acc074c109afab32d287057c3eca46
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f70ee28831acc074c109afab32d287057c3eca46" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/TwistyShakity/rust_playground 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" "+f70ee28831acc074c109afab32d287057c3eca46" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+f70ee28831acc074c109afab32d287057c3eca46" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 37e77c035f17960456ca2762b831f5ab1f57a8aa7cea92d8335ed9cadbbafd57
[INFO] running `Command { std: "docker" "start" "-a" "37e77c035f17960456ca2762b831f5ab1f57a8aa7cea92d8335ed9cadbbafd57", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "37e77c035f17960456ca2762b831f5ab1f57a8aa7cea92d8335ed9cadbbafd57", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "37e77c035f17960456ca2762b831f5ab1f57a8aa7cea92d8335ed9cadbbafd57", kill_on_drop: false }`
[INFO] [stdout] 37e77c035f17960456ca2762b831f5ab1f57a8aa7cea92d8335ed9cadbbafd57
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/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" "-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+f70ee28831acc074c109afab32d287057c3eca46" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5ef30c0138ff544ade371c774bc1e71d37f4d9c95757308f8eb2927e97540c73
[INFO] running `Command { std: "docker" "start" "-a" "5ef30c0138ff544ade371c774bc1e71d37f4d9c95757308f8eb2927e97540c73", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_playground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut some_instance = SomeStruct {
[INFO] [stdout]    |         ----^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let mut some_instance_clone = some_instance.clone();
[INFO] [stdout]    |         ----^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut some_instance = SomeStruct {
[INFO] [stdout]    |         ----^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let mut some_instance_clone = some_instance.clone();
[INFO] [stdout]    |         ----^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `int_field`, `bool_field`, and `string_field` are never read
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct SomeStruct {
[INFO] [stdout]   |        ---------- fields in this struct
[INFO] [stdout] 5 |     int_field: i32,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 6 |     bool_field: bool,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 7 |     string_field: String,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `SomeStruct` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `int_field`, `bool_field`, and `string_field` are never read
[INFO] [stdout]  --> src/main.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | struct SomeStruct {
[INFO] [stdout]   |        ---------- fields in this struct
[INFO] [stdout] 5 |     int_field: i32,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 6 |     bool_field: bool,
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 7 |     string_field: String,
[INFO] [stdout]   |     ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `SomeStruct` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] running `Command { std: "docker" "inspect" "5ef30c0138ff544ade371c774bc1e71d37f4d9c95757308f8eb2927e97540c73", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5ef30c0138ff544ade371c774bc1e71d37f4d9c95757308f8eb2927e97540c73", kill_on_drop: false }`
[INFO] [stdout] 5ef30c0138ff544ade371c774bc1e71d37f4d9c95757308f8eb2927e97540c73