[INFO] updating cached repository Ermain-12/Introduction-to-Rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Ermain-12/Introduction-to-Rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Ermain-12/Introduction-to-Rust" "work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/Ermain-12/Introduction-to-Rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/Ermain-12/Introduction-to-Rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Ermain-12/Introduction-to-Rust" "work/ex/pr-57967/sources/try#7fea0229842e79db1159ea58ad9a653b288efee9/gh/Ermain-12/Introduction-to-Rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-57967/sources/try#7fea0229842e79db1159ea58ad9a653b288efee9/gh/Ermain-12/Introduction-to-Rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 19db755187092c11f3f3ea13092682fc7bc92786
[INFO] sha for GitHub repo Ermain-12/Introduction-to-Rust: 19db755187092c11f3f3ea13092682fc7bc92786
[INFO] validating manifest of Ermain-12/Introduction-to-Rust on toolchain master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of Ermain-12/Introduction-to-Rust on toolchain try#7fea0229842e79db1159ea58ad9a653b288efee9
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+7fea0229842e79db1159ea58ad9a653b288efee9-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing Ermain-12/Introduction-to-Rust
[INFO] finished frobbing Ermain-12/Introduction-to-Rust
[INFO] frobbed toml for Ermain-12/Introduction-to-Rust written to work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/Ermain-12/Introduction-to-Rust/Cargo.toml
[INFO] started frobbing Ermain-12/Introduction-to-Rust
[INFO] finished frobbing Ermain-12/Introduction-to-Rust
[INFO] frobbed toml for Ermain-12/Introduction-to-Rust written to work/ex/pr-57967/sources/try#7fea0229842e79db1159ea58ad9a653b288efee9/gh/Ermain-12/Introduction-to-Rust/Cargo.toml
[INFO] crate Ermain-12/Introduction-to-Rust has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+7fea0229842e79db1159ea58ad9a653b288efee9-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing Ermain-12/Introduction-to-Rust against master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54 for pr-57967
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57967/worker-4/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/Ermain-12/Introduction-to-Rust:/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "build" "--frozen"`
[INFO] [stdout] 73e203e09c597a4e28645af9484b6103dd864048d78f11ef1c706785dfeab473
[INFO] running `"docker" "start" "-a" "73e203e09c597a4e28645af9484b6103dd864048d78f11ef1c706785dfeab473"`
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:27:8
[INFO] [stderr]    |
[INFO] [stderr] 27 |    let mut twenty_one = my_vec.pop();
[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]     Finished dev [unoptimized + debuginfo] target(s) in 1.45s
[INFO] running `"docker" "inspect" "73e203e09c597a4e28645af9484b6103dd864048d78f11ef1c706785dfeab473"`
[INFO] running `"docker" "rm" "-f" "73e203e09c597a4e28645af9484b6103dd864048d78f11ef1c706785dfeab473"`
[INFO] [stdout] 73e203e09c597a4e28645af9484b6103dd864048d78f11ef1c706785dfeab473
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57967/worker-4/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/Ermain-12/Introduction-to-Rust:/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "test" "--frozen" "--no-run"`
[INFO] [stdout] 70eac408032628ca34abd842a25f27773a526dbddcbffb2ded3d6d09076a0514
[INFO] running `"docker" "start" "-a" "70eac408032628ca34abd842a25f27773a526dbddcbffb2ded3d6d09076a0514"`
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:27:8
[INFO] [stderr]    |
[INFO] [stderr] 27 |    let mut twenty_one = my_vec.pop();
[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]     Finished dev [unoptimized + debuginfo] target(s) in 0.50s
[INFO] running `"docker" "inspect" "70eac408032628ca34abd842a25f27773a526dbddcbffb2ded3d6d09076a0514"`
[INFO] running `"docker" "rm" "-f" "70eac408032628ca34abd842a25f27773a526dbddcbffb2ded3d6d09076a0514"`
[INFO] [stdout] 70eac408032628ca34abd842a25f27773a526dbddcbffb2ded3d6d09076a0514
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57967/worker-4/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/Ermain-12/Introduction-to-Rust:/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "test" "--frozen"`
[INFO] [stdout] 4723b1c214311dc3cf070d639fd909fd05f1779e268cdbda25f45e088a68f3dc
[INFO] running `"docker" "start" "-a" "4723b1c214311dc3cf070d639fd909fd05f1779e268cdbda25f45e088a68f3dc"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/hello_world-b9da2636fd967e5a
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "4723b1c214311dc3cf070d639fd909fd05f1779e268cdbda25f45e088a68f3dc"`
[INFO] running `"docker" "rm" "-f" "4723b1c214311dc3cf070d639fd909fd05f1779e268cdbda25f45e088a68f3dc"`
[INFO] [stdout] 4723b1c214311dc3cf070d639fd909fd05f1779e268cdbda25f45e088a68f3dc