[INFO] updating cached repository lsaether/merkle-tree
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/lsaether/merkle-tree
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/lsaether/merkle-tree" "work/ex/beta-1.38-1/sources/1.37.0/gh/lsaether/merkle-tree"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/lsaether/merkle-tree'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/lsaether/merkle-tree" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/lsaether/merkle-tree"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/lsaether/merkle-tree'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 776dfde8ee81482edc3b2247a8658aabdddd3d61
[INFO] sha for GitHub repo lsaether/merkle-tree: 776dfde8ee81482edc3b2247a8658aabdddd3d61
[INFO] validating manifest of lsaether/merkle-tree 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 lsaether/merkle-tree 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 lsaether/merkle-tree
[INFO] finished frobbing lsaether/merkle-tree
[INFO] frobbed toml for lsaether/merkle-tree written to work/ex/beta-1.38-1/sources/1.37.0/gh/lsaether/merkle-tree/Cargo.toml
[INFO] started frobbing lsaether/merkle-tree
[INFO] finished frobbing lsaether/merkle-tree
[INFO] frobbed toml for lsaether/merkle-tree written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/lsaether/merkle-tree/Cargo.toml
[INFO] crate lsaether/merkle-tree 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing lsaether/merkle-tree 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/lsaether/merkle-tree:/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] 8a2d58c3e9886c673257a2ce7fa960001a7bc06cdbcaa76a6ac4a4c2b4680ec5
[INFO] running `"docker" "start" "-a" "8a2d58c3e9886c673257a2ce7fa960001a7bc06cdbcaa76a6ac4a4c2b4680ec5"`
[INFO] [stderr]    Compiling tiny-keccak v1.3.1
[INFO] [stderr]    Compiling hex v0.2.0
[INFO] [stderr]    Compiling merkle-tree v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0585]: found a documentation comment that doesn't document anything
[INFO] [stderr]   --> src/merkletree.rs:61:9
[INFO] [stderr]    |
[INFO] [stderr] 61 |         /// TODO
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: doc comments must come before what they document, maybe a comment was intended with `//`?
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved import `tiny_keccak`
[INFO] [stderr]  --> src/merkletree.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use tiny_keccak::Keccak;
[INFO] [stderr]   |     ^^^^^^^^^^^ help: a similar path exists: `self::tiny_keccak`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0432, E0585.
[INFO] [stderr] For more information about an error, try `rustc --explain E0432`.
[INFO] [stderr] error: Could not compile `merkle-tree`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "8a2d58c3e9886c673257a2ce7fa960001a7bc06cdbcaa76a6ac4a4c2b4680ec5"`
[INFO] running `"docker" "rm" "-f" "8a2d58c3e9886c673257a2ce7fa960001a7bc06cdbcaa76a6ac4a4c2b4680ec5"`
[INFO] [stdout] 8a2d58c3e9886c673257a2ce7fa960001a7bc06cdbcaa76a6ac4a4c2b4680ec5