[INFO] updating cached repository cowpig/go_rusty
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/cowpig/go_rusty
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/cowpig/go_rusty" "work/ex/beta-1.38-1/sources/1.37.0/gh/cowpig/go_rusty"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/cowpig/go_rusty'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/cowpig/go_rusty" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cowpig/go_rusty"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cowpig/go_rusty'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a8d7066d092fbc5dfab6974b9b22d4a519bcb7a4
[INFO] sha for GitHub repo cowpig/go_rusty: a8d7066d092fbc5dfab6974b9b22d4a519bcb7a4
[INFO] validating manifest of cowpig/go_rusty on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of cowpig/go_rusty on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing cowpig/go_rusty
[INFO] finished frobbing cowpig/go_rusty
[INFO] frobbed toml for cowpig/go_rusty written to work/ex/beta-1.38-1/sources/1.37.0/gh/cowpig/go_rusty/Cargo.toml
[INFO] started frobbing cowpig/go_rusty
[INFO] finished frobbing cowpig/go_rusty
[INFO] frobbed toml for cowpig/go_rusty written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cowpig/go_rusty/Cargo.toml
[INFO] crate cowpig/go_rusty already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing cowpig/go_rusty against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-5/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cowpig/go_rusty:/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=warn" "-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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 78838956c0b4685e8015ccaaefaf5c7cacc9a214203b37429b1cfd463ac0d2b1
[INFO] running `"docker" "start" "-a" "78838956c0b4685e8015ccaaefaf5c7cacc9a214203b37429b1cfd463ac0d2b1"`
[INFO] [stderr]    Compiling go v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/board.rs:67:25
[INFO] [stderr]    |
[INFO] [stderr] 67 |             if let Some(mut captures) = self.get_captures(
[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 1.24s
[INFO] running `"docker" "inspect" "78838956c0b4685e8015ccaaefaf5c7cacc9a214203b37429b1cfd463ac0d2b1"`
[INFO] running `"docker" "rm" "-f" "78838956c0b4685e8015ccaaefaf5c7cacc9a214203b37429b1cfd463ac0d2b1"`
[INFO] [stdout] 78838956c0b4685e8015ccaaefaf5c7cacc9a214203b37429b1cfd463ac0d2b1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-5/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cowpig/go_rusty:/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=warn" "-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" "+beta-2019-08-13" "test" "--frozen" "--no-run"`
[INFO] [stdout] d60baaf9b8c4e1900661b2abd84c13b95ebbeb504b2fff843cca29b7999852a9
[INFO] running `"docker" "start" "-a" "d60baaf9b8c4e1900661b2abd84c13b95ebbeb504b2fff843cca29b7999852a9"`
[INFO] [stderr]    Compiling go v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/board.rs:67:25
[INFO] [stderr]    |
[INFO] [stderr] 67 |             if let Some(mut captures) = self.get_captures(
[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 0.79s
[INFO] running `"docker" "inspect" "d60baaf9b8c4e1900661b2abd84c13b95ebbeb504b2fff843cca29b7999852a9"`
[INFO] running `"docker" "rm" "-f" "d60baaf9b8c4e1900661b2abd84c13b95ebbeb504b2fff843cca29b7999852a9"`
[INFO] [stdout] d60baaf9b8c4e1900661b2abd84c13b95ebbeb504b2fff843cca29b7999852a9
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-5/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cowpig/go_rusty:/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=warn" "-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" "+beta-2019-08-13" "test" "--frozen"`
[INFO] [stdout] 38ce6130386675efc7feef9f2dcf57adb9b25e33a5f21dd6739237ce89cc410e
[INFO] running `"docker" "start" "-a" "38ce6130386675efc7feef9f2dcf57adb9b25e33a5f21dd6739237ce89cc410e"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/go-59e1b97be2a2c6bc
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test it_works ... ok
[INFO] [stderr]      Running /opt/crater/target/debug/deps/go-1ba704ddee93e5d2
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests go
[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] [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" "38ce6130386675efc7feef9f2dcf57adb9b25e33a5f21dd6739237ce89cc410e"`
[INFO] running `"docker" "rm" "-f" "38ce6130386675efc7feef9f2dcf57adb9b25e33a5f21dd6739237ce89cc410e"`
[INFO] [stdout] 38ce6130386675efc7feef9f2dcf57adb9b25e33a5f21dd6739237ce89cc410e