[INFO] updating cached repository MonadProject/ledger
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/MonadProject/ledger
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/MonadProject/ledger" "work/ex/beta-1.38-1/sources/1.37.0/gh/MonadProject/ledger"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/MonadProject/ledger'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/MonadProject/ledger" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/MonadProject/ledger"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/MonadProject/ledger'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d8f25f9c9aef42eac40cd7da448105b8c1ef4406
[INFO] sha for GitHub repo MonadProject/ledger: d8f25f9c9aef42eac40cd7da448105b8c1ef4406
[INFO] validating manifest of MonadProject/ledger 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 MonadProject/ledger 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 MonadProject/ledger
[INFO] finished frobbing MonadProject/ledger
[INFO] frobbed toml for MonadProject/ledger written to work/ex/beta-1.38-1/sources/1.37.0/gh/MonadProject/ledger/Cargo.toml
[INFO] started frobbing MonadProject/ledger
[INFO] finished frobbing MonadProject/ledger
[INFO] frobbed toml for MonadProject/ledger written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/MonadProject/ledger/Cargo.toml
[INFO] crate MonadProject/ledger 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 MonadProject/ledger 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-4/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/MonadProject/ledger:/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] 17ab05bb999291db0e7b29c1d54f27107cf5ebdf1612ea4452e2b43040f67360
[INFO] running `"docker" "start" "-a" "17ab05bb999291db0e7b29c1d54f27107cf5ebdf1612ea4452e2b43040f67360"`
[INFO] [stderr]    Compiling monadledger v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]  --> src/main.rs:3:9
[INFO] [stderr]   |
[INFO] [stderr] 3 |     let b = &&a[0];
[INFO] [stderr]   |         ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.86s
[INFO] running `"docker" "inspect" "17ab05bb999291db0e7b29c1d54f27107cf5ebdf1612ea4452e2b43040f67360"`
[INFO] running `"docker" "rm" "-f" "17ab05bb999291db0e7b29c1d54f27107cf5ebdf1612ea4452e2b43040f67360"`
[INFO] [stdout] 17ab05bb999291db0e7b29c1d54f27107cf5ebdf1612ea4452e2b43040f67360
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/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/MonadProject/ledger:/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] af11d34ec30f807ed733b21bf5e0936739a692e3d72c8776b62d446416be7b01
[INFO] running `"docker" "start" "-a" "af11d34ec30f807ed733b21bf5e0936739a692e3d72c8776b62d446416be7b01"`
[INFO] [stderr]    Compiling monadledger v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]  --> src/main.rs:3:9
[INFO] [stderr]   |
[INFO] [stderr] 3 |     let b = &&a[0];
[INFO] [stderr]   |         ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.80s
[INFO] running `"docker" "inspect" "af11d34ec30f807ed733b21bf5e0936739a692e3d72c8776b62d446416be7b01"`
[INFO] running `"docker" "rm" "-f" "af11d34ec30f807ed733b21bf5e0936739a692e3d72c8776b62d446416be7b01"`
[INFO] [stdout] af11d34ec30f807ed733b21bf5e0936739a692e3d72c8776b62d446416be7b01
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/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/MonadProject/ledger:/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] 2601932fd0cbd0eb00523ac6cfd9848f21324494428441bd8638075261b03841
[INFO] running `"docker" "start" "-a" "2601932fd0cbd0eb00523ac6cfd9848f21324494428441bd8638075261b03841"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.03s
[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] [stderr]      Running /opt/crater/target/debug/deps/monadledger-7b83f357e5479929
[INFO] running `"docker" "inspect" "2601932fd0cbd0eb00523ac6cfd9848f21324494428441bd8638075261b03841"`
[INFO] running `"docker" "rm" "-f" "2601932fd0cbd0eb00523ac6cfd9848f21324494428441bd8638075261b03841"`
[INFO] [stdout] 2601932fd0cbd0eb00523ac6cfd9848f21324494428441bd8638075261b03841