[INFO] updating cached repository a7p/learn-rust-stringmixer
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/a7p/learn-rust-stringmixer
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/a7p/learn-rust-stringmixer" "work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/a7p/learn-rust-stringmixer"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/a7p/learn-rust-stringmixer'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/a7p/learn-rust-stringmixer" "work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/a7p/learn-rust-stringmixer"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/a7p/learn-rust-stringmixer'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] fcb40481b878e6596a5284902fa4cf1a2a04252e
[INFO] sha for GitHub repo a7p/learn-rust-stringmixer: fcb40481b878e6596a5284902fa4cf1a2a04252e
[INFO] validating manifest of a7p/learn-rust-stringmixer on toolchain master#60960a260f7b5c695fd0717311d72ce62dd4eb43
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of a7p/learn-rust-stringmixer on toolchain try#266783e4e09e4e9d5307c1c8e695659c58bbcac7
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing a7p/learn-rust-stringmixer
[INFO] finished frobbing a7p/learn-rust-stringmixer
[INFO] frobbed toml for a7p/learn-rust-stringmixer written to work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/a7p/learn-rust-stringmixer/Cargo.toml
[INFO] started frobbing a7p/learn-rust-stringmixer
[INFO] finished frobbing a7p/learn-rust-stringmixer
[INFO] frobbed toml for a7p/learn-rust-stringmixer written to work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/a7p/learn-rust-stringmixer/Cargo.toml
[INFO] crate a7p/learn-rust-stringmixer already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/a7p/learn-rust-stringmixer/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking a7p/learn-rust-stringmixer against try#266783e4e09e4e9d5307c1c8e695659c58bbcac7 for pr-63376
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-63376/worker-3/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/a7p/learn-rust-stringmixer:/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" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 38a2f597bd3d97bd83855f342c6ff573f01f67d6f47e3b973535c66974fe681c
[INFO] running `"docker" "start" "-a" "38a2f597bd3d97bd83855f342c6ff573f01f67d6f47e3b973535c66974fe681c"`
[INFO] [stderr]     Checking stringmixer v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:20:13
[INFO] [stderr]    |
[INFO] [stderr] 20 |         let mut v = &mut g[1..l];
[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:20:13
[INFO] [stderr]    |
[INFO] [stderr] 20 |         let mut v = &mut g[1..l];
[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 0.81s
[INFO] running `"docker" "inspect" "38a2f597bd3d97bd83855f342c6ff573f01f67d6f47e3b973535c66974fe681c"`
[INFO] running `"docker" "rm" "-f" "38a2f597bd3d97bd83855f342c6ff573f01f67d6f47e3b973535c66974fe681c"`
[INFO] [stdout] 38a2f597bd3d97bd83855f342c6ff573f01f67d6f47e3b973535c66974fe681c