[INFO] updating cached repository https://github.com/Pratyush/snark-tutorial
[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] 72d0f74366e9d11576f8f6a546b40040ca0d55a3
[INFO] testing Pratyush/snark-tutorial against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2FPratyush%2Fsnark-tutorial" "work/builds/worker-6/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Pratyush/snark-tutorial 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/Pratyush/snark-tutorial
[INFO] finished tweaking git repo https://github.com/Pratyush/snark-tutorial
[INFO] tweaked toml for git repo https://github.com/Pratyush/snark-tutorial written to work/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/Pratyush/snark-tutorial 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-6/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] fa7df8211e027fae71ac48ac5e9d29f6ea7d7a8b23d0945b2167a2a89febc076
[INFO] running `"docker" "start" "-a" "fa7df8211e027fae71ac48ac5e9d29f6ea7d7a8b23d0945b2167a2a89febc076"`
[INFO] [stderr]    Compiling bench-utils v0.1.0 (https://github.com/scipr-lab/zexe#0685bd1b)
[INFO] [stderr]    Compiling rand_derive v0.3.1
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling crossbeam-deque v0.6.3
[INFO] [stderr]    Compiling derivative v1.0.2
[INFO] [stderr]    Compiling rayon-core v1.5.0
[INFO] [stderr]    Compiling rayon v1.1.0
[INFO] [stderr]    Compiling algebra v0.1.0 (https://github.com/scipr-lab/zexe#0685bd1b)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/git/checkouts/zexe-f74c42809fa6cfe1/0685bd1/algebra/src/lib.rs:35:1
[INFO] [stderr]    |
[INFO] [stderr] 35 | #![feature(const_fn)]
[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 `algebra`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "fa7df8211e027fae71ac48ac5e9d29f6ea7d7a8b23d0945b2167a2a89febc076"`
[INFO] running `"docker" "rm" "-f" "fa7df8211e027fae71ac48ac5e9d29f6ea7d7a8b23d0945b2167a2a89febc076"`
[INFO] [stdout] fa7df8211e027fae71ac48ac5e9d29f6ea7d7a8b23d0945b2167a2a89febc076