[INFO] updating cached repository GTxx/learn_rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/GTxx/learn_rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/GTxx/learn_rust" "work/ex/beta-1.38-1/sources/1.37.0/gh/GTxx/learn_rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/GTxx/learn_rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/GTxx/learn_rust" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/GTxx/learn_rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/GTxx/learn_rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b4dc2ad0d71f20b8eb03792f5b8269ce8d7cb321
[INFO] sha for GitHub repo GTxx/learn_rust: b4dc2ad0d71f20b8eb03792f5b8269ce8d7cb321
[INFO] validating manifest of GTxx/learn_rust 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 GTxx/learn_rust 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 GTxx/learn_rust
[INFO] finished frobbing GTxx/learn_rust
[INFO] frobbed toml for GTxx/learn_rust written to work/ex/beta-1.38-1/sources/1.37.0/gh/GTxx/learn_rust/Cargo.toml
[INFO] started frobbing GTxx/learn_rust
[INFO] finished frobbing GTxx/learn_rust
[INFO] frobbed toml for GTxx/learn_rust written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/GTxx/learn_rust/Cargo.toml
[INFO] crate GTxx/learn_rust 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 GTxx/learn_rust 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-7/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/GTxx/learn_rust:/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] 62a43ffcacb71c2018fb75bb2c123c6cbd6068752931f8e235669b3700da3c75
[INFO] running `"docker" "start" "-a" "62a43ffcacb71c2018fb75bb2c123c6cbd6068752931f8e235669b3700da3c75"`
[INFO] [stderr]    Compiling learn_rust v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0603]: function `find_queen_position` is private
[INFO] [stderr]  --> src/main.rs:5:12
[INFO] [stderr]   |
[INFO] [stderr] 5 | use queen::find_queen_position; 
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]   --> src/queen.rs:26:12
[INFO] [stderr]    |
[INFO] [stderr] 18 | fn find_queen_position(result: Vec<Location>, row: i8) -> HashSet<i8>{
[INFO] [stderr]    |                                                           ----------- expected `std::collections::HashSet<i8>` because of return type
[INFO] [stderr] ...
[INFO] [stderr] 26 |     return available_col.difference(&disabled_col)
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `std::collections::HashSet`, found struct `std::collections::hash_set::Difference`
[INFO] [stderr]    |
[INFO] [stderr]    = note: expected type `std::collections::HashSet<i8>`
[INFO] [stderr]               found type `std::collections::hash_set::Difference<'_, i8, std::collections::hash_map::RandomState>`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0308, E0603.
[INFO] [stderr] For more information about an error, try `rustc --explain E0308`.
[INFO] [stderr] error: Could not compile `learn_rust`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "62a43ffcacb71c2018fb75bb2c123c6cbd6068752931f8e235669b3700da3c75"`
[INFO] running `"docker" "rm" "-f" "62a43ffcacb71c2018fb75bb2c123c6cbd6068752931f8e235669b3700da3c75"`
[INFO] [stdout] 62a43ffcacb71c2018fb75bb2c123c6cbd6068752931f8e235669b3700da3c75