[INFO] updating cached repository ahouts/math166-assignment2
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/ahouts/math166-assignment2
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/ahouts/math166-assignment2" "work/ex/beta-1.37-6/sources/1.36.0/gh/ahouts/math166-assignment2"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/ahouts/math166-assignment2'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/ahouts/math166-assignment2" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/ahouts/math166-assignment2"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/ahouts/math166-assignment2'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 4a89187ef91f6b75d3c9e649207e8b1b98a8efbc
[INFO] sha for GitHub repo ahouts/math166-assignment2: 4a89187ef91f6b75d3c9e649207e8b1b98a8efbc
[INFO] validating manifest of ahouts/math166-assignment2 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of ahouts/math166-assignment2 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing ahouts/math166-assignment2
[INFO] finished frobbing ahouts/math166-assignment2
[INFO] frobbed toml for ahouts/math166-assignment2 written to work/ex/beta-1.37-6/sources/1.36.0/gh/ahouts/math166-assignment2/Cargo.toml
[INFO] started frobbing ahouts/math166-assignment2
[INFO] finished frobbing ahouts/math166-assignment2
[INFO] frobbed toml for ahouts/math166-assignment2 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/ahouts/math166-assignment2/Cargo.toml
[INFO] crate ahouts/math166-assignment2 already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing ahouts/math166-assignment2 against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/ahouts/math166-assignment2:/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-2019-07-23" "build" "--frozen"`
[INFO] [stdout] 0db171e9ae1c2af86782237d6f73e2067f25d669b6bd1f27be6d8710341cc574
[INFO] running `"docker" "start" "-a" "0db171e9ae1c2af86782237d6f73e2067f25d669b6bd1f27be6d8710341cc574"`
[INFO] [stderr]    Compiling math166-assignment2 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: struct is never constructed: `ReverseSub`
[INFO] [stderr]   --> src/mat_eqn_solver.rs:13:1
[INFO] [stderr]    |
[INFO] [stderr] 13 | pub struct ReverseSub<T: UpperTriangle> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.09s
[INFO] running `"docker" "inspect" "0db171e9ae1c2af86782237d6f73e2067f25d669b6bd1f27be6d8710341cc574"`
[INFO] running `"docker" "rm" "-f" "0db171e9ae1c2af86782237d6f73e2067f25d669b6bd1f27be6d8710341cc574"`
[INFO] [stdout] 0db171e9ae1c2af86782237d6f73e2067f25d669b6bd1f27be6d8710341cc574
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/ahouts/math166-assignment2:/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-2019-07-23" "test" "--frozen" "--no-run"`
[INFO] [stdout] 82ddb3f0b93970846b00d41dfea01ea936774dac982aae451da193adfa654847
[INFO] running `"docker" "start" "-a" "82ddb3f0b93970846b00d41dfea01ea936774dac982aae451da193adfa654847"`
[INFO] [stderr]    Compiling math166-assignment2 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: struct is never constructed: `ReverseSub`
[INFO] [stderr]   --> src/mat_eqn_solver.rs:13:1
[INFO] [stderr]    |
[INFO] [stderr] 13 | pub struct ReverseSub<T: UpperTriangle> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `"docker" "inspect" "82ddb3f0b93970846b00d41dfea01ea936774dac982aae451da193adfa654847"`
[INFO] running `"docker" "rm" "-f" "82ddb3f0b93970846b00d41dfea01ea936774dac982aae451da193adfa654847"`
[INFO] [stdout] 82ddb3f0b93970846b00d41dfea01ea936774dac982aae451da193adfa654847
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/ahouts/math166-assignment2:/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-2019-07-23" "test" "--frozen"`
[INFO] [stdout] 1d724f878a6619da352d6d1d748fd6d9508dead000e754fca32e0be6700744dd
[INFO] running `"docker" "start" "-a" "1d724f878a6619da352d6d1d748fd6d9508dead000e754fca32e0be6700744dd"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/math166_assignment2-d3a0786a8f11134a
[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" "1d724f878a6619da352d6d1d748fd6d9508dead000e754fca32e0be6700744dd"`
[INFO] running `"docker" "rm" "-f" "1d724f878a6619da352d6d1d748fd6d9508dead000e754fca32e0be6700744dd"`
[INFO] [stdout] 1d724f878a6619da352d6d1d748fd6d9508dead000e754fca32e0be6700744dd