[INFO] updating cached repository https://github.com/gavrielrh/recursion-benchmarking
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 6f644eff389f2be894220286d15a11328cf141b6
[INFO] testing gavrielrh/recursion-benchmarking against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgavrielrh%2Frecursion-benchmarking" "work/builds/worker-2/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/gavrielrh/recursion-benchmarking on toolchain beta-2019-09-28
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/gavrielrh/recursion-benchmarking
[INFO] finished tweaking git repo https://github.com/gavrielrh/recursion-benchmarking
[INFO] tweaked toml for git repo https://github.com/gavrielrh/recursion-benchmarking written to work/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/gavrielrh/recursion-benchmarking already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2019-09-28" "build" "--frozen"`
[INFO] [stdout] 676ff19768f622415d83487fd019007a2138798c610fcd34ee073eb1aa76f3c2
[INFO] running `"docker" "start" "-a" "676ff19768f622415d83487fd019007a2138798c610fcd34ee073eb1aa76f3c2"`
[INFO] [stderr]    Compiling recursion v0.1.0 (/opt/rustwide/workdir)
[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(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `rand::Rng`
[INFO] [stderr]   --> src/main.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 | use rand::Rng;
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[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 `recursion`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "676ff19768f622415d83487fd019007a2138798c610fcd34ee073eb1aa76f3c2"`
[INFO] running `"docker" "rm" "-f" "676ff19768f622415d83487fd019007a2138798c610fcd34ee073eb1aa76f3c2"`
[INFO] [stdout] 676ff19768f622415d83487fd019007a2138798c610fcd34ee073eb1aa76f3c2