[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-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/Ermain-12/Introduction-to-Rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/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-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/Ermain-12/Introduction-to-Rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/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#e2f221c75932de7a29845c8d6f1f73536ad00c41
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e2f221c75932de7a29845c8d6f1f73536ad00c41-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of Ermain-12/Introduction-to-Rust on toolchain try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0bfb90d213a93e466b33d078a5b535a2a6f9c5ff-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-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/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-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/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" "+e2f221c75932de7a29845c8d6f1f73536ad00c41-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0bfb90d213a93e466b33d078a5b535a2a6f9c5ff-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking Ermain-12/Introduction-to-Rust against try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff for pr-57617
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57617/worker-3/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/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" "+0bfb90d213a93e466b33d078a5b535a2a6f9c5ff-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 0b3315b1d6c969efb743e310b85be43d1cf06e43bc3e55fd768532dadcaf69cf
[INFO] running `"docker" "start" "-a" "0b3315b1d6c969efb743e310b85be43d1cf06e43bc3e55fd768532dadcaf69cf"`
[INFO] [stderr]     Checking 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] 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 0.75s
[INFO] running `"docker" "inspect" "0b3315b1d6c969efb743e310b85be43d1cf06e43bc3e55fd768532dadcaf69cf"`
[INFO] running `"docker" "rm" "-f" "0b3315b1d6c969efb743e310b85be43d1cf06e43bc3e55fd768532dadcaf69cf"`
[INFO] [stdout] 0b3315b1d6c969efb743e310b85be43d1cf06e43bc3e55fd768532dadcaf69cf