[INFO] updating cached repository alevy/iterator_bench
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/alevy/iterator_bench
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/alevy/iterator_bench" "work/ex/beta-1.38-1/sources/1.37.0/gh/alevy/iterator_bench"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/alevy/iterator_bench'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/alevy/iterator_bench" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/alevy/iterator_bench"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/alevy/iterator_bench'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 026d67b174f1304e34626850dcc9c3aecc155f2b
[INFO] sha for GitHub repo alevy/iterator_bench: 026d67b174f1304e34626850dcc9c3aecc155f2b
[INFO] validating manifest of alevy/iterator_bench 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 alevy/iterator_bench 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 alevy/iterator_bench
[INFO] finished frobbing alevy/iterator_bench
[INFO] frobbed toml for alevy/iterator_bench written to work/ex/beta-1.38-1/sources/1.37.0/gh/alevy/iterator_bench/Cargo.toml
[INFO] started frobbing alevy/iterator_bench
[INFO] finished frobbing alevy/iterator_bench
[INFO] frobbed toml for alevy/iterator_bench written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/alevy/iterator_bench/Cargo.toml
[INFO] crate alevy/iterator_bench 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 alevy/iterator_bench 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/alevy/iterator_bench:/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] d775ea5d6176d45efc8c614a31bafbd604eb72b769a674ac4e6cbffc0439abae
[INFO] running `"docker" "start" "-a" "d775ea5d6176d45efc8c614a31bafbd604eb72b769a674ac4e6cbffc0439abae"`
[INFO] [stderr]    Compiling iterator_bench v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> src/main.rs:63:1
[INFO] [stderr]    |
[INFO] [stderr] 63 | / /// This is the implementation we would write in C.
[INFO] [stderr] 64 | | ///
[INFO] [stderr] 65 | | ///   * It iterators over the input array with a C-style for-loop.
[INFO] [stderr] 66 | | ///
[INFO] [stderr] ...  |
[INFO] [stderr] 77 | | /// The compiler has managed to compile this into packed moves. So there are only 20,000 iterations
[INFO] [stderr] 78 | | /// of the loop with 5 instructions each.
[INFO] [stderr]    | |_________________________________________^
[INFO] [stderr] 79 | / benchmark!(
[INFO] [stderr] 80 | |     optimal_unsafe,
[INFO] [stderr] 81 | |     [u8; 640000],
[INFO] [stderr] 82 | |     [u16; 320000],
[INFO] [stderr] ...  |
[INFO] [stderr] 89 | |     }
[INFO] [stderr] 90 | | );
[INFO] [stderr]    | |__- rustdoc does not generate documentation for macro expansions
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stderr]    = help: to document an item produced by a macro, the macro must produce the documentation as part of its expansion
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(stmt_expr_attributes, test)]
[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 `iterator_bench`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "d775ea5d6176d45efc8c614a31bafbd604eb72b769a674ac4e6cbffc0439abae"`
[INFO] running `"docker" "rm" "-f" "d775ea5d6176d45efc8c614a31bafbd604eb72b769a674ac4e6cbffc0439abae"`
[INFO] [stdout] d775ea5d6176d45efc8c614a31bafbd604eb72b769a674ac4e6cbffc0439abae