[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 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] f9965f5e5151e8092e9b4c43f79f02540e592647cdc50bccfbab13c3e327e985
[INFO] running `"docker" "start" "-a" "f9965f5e5151e8092e9b4c43f79f02540e592647cdc50bccfbab13c3e327e985"`
[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 1.17s
[INFO] running `"docker" "inspect" "f9965f5e5151e8092e9b4c43f79f02540e592647cdc50bccfbab13c3e327e985"`
[INFO] running `"docker" "rm" "-f" "f9965f5e5151e8092e9b4c43f79f02540e592647cdc50bccfbab13c3e327e985"`
[INFO] [stdout] f9965f5e5151e8092e9b4c43f79f02540e592647cdc50bccfbab13c3e327e985
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/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" "+1.37.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] ab2b7a462cd29c4cd3acd30ad1e3299b8f9c2afb69dbe3247a32fb7600df1d4a
[INFO] running `"docker" "start" "-a" "ab2b7a462cd29c4cd3acd30ad1e3299b8f9c2afb69dbe3247a32fb7600df1d4a"`
[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 0.91s
[INFO] running `"docker" "inspect" "ab2b7a462cd29c4cd3acd30ad1e3299b8f9c2afb69dbe3247a32fb7600df1d4a"`
[INFO] running `"docker" "rm" "-f" "ab2b7a462cd29c4cd3acd30ad1e3299b8f9c2afb69dbe3247a32fb7600df1d4a"`
[INFO] [stdout] ab2b7a462cd29c4cd3acd30ad1e3299b8f9c2afb69dbe3247a32fb7600df1d4a
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/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" "+1.37.0" "test" "--frozen"`
[INFO] [stdout] fb7a6c1f72df6459d62dff50507a1d1c1e21bc726201575436c7042c84ff856d
[INFO] running `"docker" "start" "-a" "fb7a6c1f72df6459d62dff50507a1d1c1e21bc726201575436c7042c84ff856d"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/go-bb5ccc8d63581ee0
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test it_works ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/crater/target/debug/deps/go-9d87346b10b25522
[INFO] [stdout] running 0 tests
[INFO] [stderr]    Doc-tests go
[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" "fb7a6c1f72df6459d62dff50507a1d1c1e21bc726201575436c7042c84ff856d"`
[INFO] running `"docker" "rm" "-f" "fb7a6c1f72df6459d62dff50507a1d1c1e21bc726201575436c7042c84ff856d"`
[INFO] [stdout] fb7a6c1f72df6459d62dff50507a1d1c1e21bc726201575436c7042c84ff856d