[INFO] updating cached repository benaryorg/rust-loop_benchmarking
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/benaryorg/rust-loop_benchmarking
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/benaryorg/rust-loop_benchmarking" "work/ex/beta-1.38-1/sources/1.37.0/gh/benaryorg/rust-loop_benchmarking"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/benaryorg/rust-loop_benchmarking'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/benaryorg/rust-loop_benchmarking" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/benaryorg/rust-loop_benchmarking"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/benaryorg/rust-loop_benchmarking'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 80cf66c5aa1e00a647c0b89f82efed88bfac73e3
[INFO] sha for GitHub repo benaryorg/rust-loop_benchmarking: 80cf66c5aa1e00a647c0b89f82efed88bfac73e3
[INFO] validating manifest of benaryorg/rust-loop_benchmarking 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 benaryorg/rust-loop_benchmarking 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 benaryorg/rust-loop_benchmarking
[INFO] finished frobbing benaryorg/rust-loop_benchmarking
[INFO] frobbed toml for benaryorg/rust-loop_benchmarking written to work/ex/beta-1.38-1/sources/1.37.0/gh/benaryorg/rust-loop_benchmarking/Cargo.toml
[INFO] started frobbing benaryorg/rust-loop_benchmarking
[INFO] finished frobbing benaryorg/rust-loop_benchmarking
[INFO] frobbed toml for benaryorg/rust-loop_benchmarking written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/benaryorg/rust-loop_benchmarking/Cargo.toml
[INFO] crate benaryorg/rust-loop_benchmarking 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 benaryorg/rust-loop_benchmarking 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/benaryorg/rust-loop_benchmarking:/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] 982a25b818d73e2e00bcc414510bef304e930055046ac91b2b4c9935f106f39f
[INFO] running `"docker" "start" "-a" "982a25b818d73e2e00bcc414510bef304e930055046ac91b2b4c9935f106f39f"`
[INFO] [stderr]    Compiling loop v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(step_by)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `loop`
[INFO] [stderr]   |
[INFO] [stderr]   = note: consider adding a `main` function to `src/main.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0601.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `loop`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "982a25b818d73e2e00bcc414510bef304e930055046ac91b2b4c9935f106f39f"`
[INFO] running `"docker" "rm" "-f" "982a25b818d73e2e00bcc414510bef304e930055046ac91b2b4c9935f106f39f"`
[INFO] [stdout] 982a25b818d73e2e00bcc414510bef304e930055046ac91b2b4c9935f106f39f