[INFO] updating cached repository Snektron/mamba
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Snektron/mamba
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Snektron/mamba" "work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/Snektron/mamba"`
[INFO] [stderr] Cloning into 'work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/Snektron/mamba'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Snektron/mamba" "work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/Snektron/mamba"`
[INFO] [stderr] Cloning into 'work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/Snektron/mamba'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8e16034b3ed9bcf9a5a92b15d9ce65d3bcf8360e
[INFO] sha for GitHub repo Snektron/mamba: 8e16034b3ed9bcf9a5a92b15d9ce65d3bcf8360e
[INFO] validating manifest of Snektron/mamba on toolchain master#5f9c0448dde167128d668da4555879f64e56af1d
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of Snektron/mamba on toolchain try#8ec8125bea94852768b56958f05da47666c21ab0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing Snektron/mamba
[INFO] finished frobbing Snektron/mamba
[INFO] frobbed toml for Snektron/mamba written to work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/Snektron/mamba/Cargo.toml
[INFO] started frobbing Snektron/mamba
[INFO] finished frobbing Snektron/mamba
[INFO] frobbed toml for Snektron/mamba written to work/ex/pr-62133/sources/try#8ec8125bea94852768b56958f05da47666c21ab0/gh/Snektron/mamba/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+8ec8125bea94852768b56958f05da47666c21ab0-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking Snektron/mamba against master#5f9c0448dde167128d668da4555879f64e56af1d for pr-62133
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-62133/worker-0/master#5f9c0448dde167128d668da4555879f64e56af1d:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-62133/sources/master#5f9c0448dde167128d668da4555879f64e56af1d/gh/Snektron/mamba:/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" "+5f9c0448dde167128d668da4555879f64e56af1d-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 7b046e7b950c8ad8083ac93743e5c72780bff2709a1f1abaae7b4916ed522642
[INFO] running `"docker" "start" "-a" "7b046e7b950c8ad8083ac93743e5c72780bff2709a1f1abaae7b4916ed522642"`
[INFO] [stderr]    Compiling bit-vec v0.5.1
[INFO] [stderr]    Compiling strsim v0.9.2
[INFO] [stderr]    Compiling block-padding v0.1.4
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling ena v0.11.0
[INFO] [stderr]    Compiling string_cache_codegen v0.4.2
[INFO] [stderr]    Compiling serde v1.0.94
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling bit-set v0.5.1
[INFO] [stderr]    Compiling sha2 v0.8.0
[INFO] [stderr]    Compiling string_cache v0.7.3
[INFO] [stderr]    Compiling docopt v1.1.0
[INFO] [stderr]    Compiling lalrpop v0.16.3
[INFO] [stderr]    Compiling mamba v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/ast/construct.rs:188:13
[INFO] [stderr]     |
[INFO] [stderr] 188 |         let mut t = check_arms(&from, arms, &states, &alphabet)?;
[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/ast/construct.rs:188:13
[INFO] [stderr]     |
[INFO] [stderr] 188 |         let mut t = check_arms(&from, arms, &states, &alphabet)?;
[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 1m 23s
[INFO] running `"docker" "inspect" "7b046e7b950c8ad8083ac93743e5c72780bff2709a1f1abaae7b4916ed522642"`
[INFO] running `"docker" "rm" "-f" "7b046e7b950c8ad8083ac93743e5c72780bff2709a1f1abaae7b4916ed522642"`
[INFO] [stdout] 7b046e7b950c8ad8083ac93743e5c72780bff2709a1f1abaae7b4916ed522642