[INFO] updating cached repository cjm00/rust-wfc
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/cjm00/rust-wfc
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/cjm00/rust-wfc" "work/ex/beta-1.38-1/sources/1.37.0/gh/cjm00/rust-wfc"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/cjm00/rust-wfc'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/cjm00/rust-wfc" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cjm00/rust-wfc"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cjm00/rust-wfc'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 76b262ba3707afe22f6a6d8a9699aa9413d91955
[INFO] sha for GitHub repo cjm00/rust-wfc: 76b262ba3707afe22f6a6d8a9699aa9413d91955
[INFO] validating manifest of cjm00/rust-wfc 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 cjm00/rust-wfc 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 cjm00/rust-wfc
[INFO] finished frobbing cjm00/rust-wfc
[INFO] frobbed toml for cjm00/rust-wfc written to work/ex/beta-1.38-1/sources/1.37.0/gh/cjm00/rust-wfc/Cargo.toml
[INFO] started frobbing cjm00/rust-wfc
[INFO] finished frobbing cjm00/rust-wfc
[INFO] frobbed toml for cjm00/rust-wfc written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/cjm00/rust-wfc/Cargo.toml
[INFO] crate cjm00/rust-wfc 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 cjm00/rust-wfc 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-0/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/cjm00/rust-wfc:/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] 4c665a708390808f31494d832fdf67a2534052953bedbc8ecc784f4bf5011d38
[INFO] running `"docker" "start" "-a" "4c665a708390808f31494d832fdf67a2534052953bedbc8ecc784f4bf5011d38"`
[INFO] [stderr]    Compiling either v1.1.0
[INFO] [stderr]    Compiling ndarray v0.9.0
[INFO] [stderr]    Compiling bit-vec v0.4.3
[INFO] [stderr]    Compiling num-integer v0.1.33
[INFO] [stderr]    Compiling num-complex v0.1.37
[INFO] [stderr]    Compiling time v0.1.36
[INFO] [stderr]    Compiling deflate v0.7.5
[INFO] [stderr]    Compiling itertools v0.6.0
[INFO] [stderr]    Compiling num-iter v0.1.33
[INFO] [stderr]    Compiling num v0.1.36
[INFO] [stderr]    Compiling png v0.6.2
[INFO] [stderr]    Compiling chrono v0.3.0
[INFO] [stderr]    Compiling rust-wfc v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> src/overlappingmodel.rs:88:9
[INFO] [stderr]    |
[INFO] [stderr] 88 | /         /// Marks all but a single state of the BitVec as forbidden, randomly chosen
[INFO] [stderr] 89 | |         /// from the states still permitted and weighted by their frequency in the original image.
[INFO] [stderr]    | |__________________________________________________________________________________________________^
[INFO] [stderr] 90 |           let mut possible_states = self.possible_states.borrow_mut();
[INFO] [stderr]    |           ------------------------------------------------------------ rustdoc does not generate documentation for statements
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> src/utils.rs:40:5
[INFO] [stderr]    |
[INFO] [stderr] 40 | /     /// Returns an index from the slice of (T, u) where u is the integer weight, i.e.
[INFO] [stderr] 41 | |     /// [('a', 3), ('b', 1), ('c', 1)] returns 0 (the index of 'a') with probability 3/5
[INFO] [stderr]    | |________________________________________________________________________________________^
[INFO] [stderr] 42 | 
[INFO] [stderr] 43 | /     let total: usize = input.iter()
[INFO] [stderr] 44 | |         .map(|&(_, u)| u)
[INFO] [stderr] 45 | |         .zip(mask.into_iter())
[INFO] [stderr] 46 | |         .filter(|&(_, m)| m)
[INFO] [stderr] 47 | |         .map(|(u, _)| u)
[INFO] [stderr] 48 | |         .sum();
[INFO] [stderr]    | |_______________- rustdoc does not generate documentation for statements
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(try_from)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rust-wfc`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "4c665a708390808f31494d832fdf67a2534052953bedbc8ecc784f4bf5011d38"`
[INFO] running `"docker" "rm" "-f" "4c665a708390808f31494d832fdf67a2534052953bedbc8ecc784f4bf5011d38"`
[INFO] [stdout] 4c665a708390808f31494d832fdf67a2534052953bedbc8ecc784f4bf5011d38