[INFO] updating cached repository mtn/silver
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/mtn/silver
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/mtn/silver" "work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/mtn/silver"`
[INFO] [stderr] Cloning into 'work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/mtn/silver'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/mtn/silver" "work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/mtn/silver"`
[INFO] [stderr] Cloning into 'work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/mtn/silver'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 895c666723d96cf42655ef713ff9893b25f10b3c
[INFO] sha for GitHub repo mtn/silver: 895c666723d96cf42655ef713ff9893b25f10b3c
[INFO] validating manifest of mtn/silver 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 mtn/silver 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 mtn/silver
[INFO] finished frobbing mtn/silver
[INFO] frobbed toml for mtn/silver written to work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/mtn/silver/Cargo.toml
[INFO] started frobbing mtn/silver
[INFO] finished frobbing mtn/silver
[INFO] frobbed toml for mtn/silver written to work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/mtn/silver/Cargo.toml
[INFO] crate mtn/silver 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 mtn/silver 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/mtn/silver:/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] 0a58d12e17168c7eaf752269ebe6da3afcdcffa72cdeb7a42d9d6d03296023e4
[INFO] running `"docker" "start" "-a" "0a58d12e17168c7eaf752269ebe6da3afcdcffa72cdeb7a42d9d6d03296023e4"`
[INFO] [stderr]     Checking silver v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:331:13
[INFO] [stderr]     |
[INFO] [stderr] 331 |         let mut lexer = lexer::Lexer::new(inp);
[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/parser.rs:344:13
[INFO] [stderr]     |
[INFO] [stderr] 344 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:366:13
[INFO] [stderr]     |
[INFO] [stderr] 366 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:385:13
[INFO] [stderr]     |
[INFO] [stderr] 385 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:406:13
[INFO] [stderr]     |
[INFO] [stderr] 406 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:430:13
[INFO] [stderr]     |
[INFO] [stderr] 430 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:451:13
[INFO] [stderr]     |
[INFO] [stderr] 451 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/parser.rs:487:13
[INFO] [stderr]     |
[INFO] [stderr] 487 |         let mut lexer = lexer::Lexer::new(inp);
[INFO] [stderr]     |             ----^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.61s
[INFO] running `"docker" "inspect" "0a58d12e17168c7eaf752269ebe6da3afcdcffa72cdeb7a42d9d6d03296023e4"`
[INFO] running `"docker" "rm" "-f" "0a58d12e17168c7eaf752269ebe6da3afcdcffa72cdeb7a42d9d6d03296023e4"`
[INFO] [stdout] 0a58d12e17168c7eaf752269ebe6da3afcdcffa72cdeb7a42d9d6d03296023e4