[INFO] updating cached repository https://github.com/echochamber/rust_hex_grid
[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] c9e98f95bec77dffde5ef30c8501badd56773904
[INFO] testing echochamber/rust_hex_grid against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Frust_hex_grid" "work/builds/worker-7/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/echochamber/rust_hex_grid 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/echochamber/rust_hex_grid
[INFO] finished tweaking git repo https://github.com/echochamber/rust_hex_grid
[INFO] tweaked toml for git repo https://github.com/echochamber/rust_hex_grid written to work/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/echochamber/rust_hex_grid 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] error: the lock file /big/crater/work/builds/worker-7/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-7/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-7/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] 0c6b59c11d50cb0a452fb9a32cdefc37ed23a7df40f11063de7b307d864f7959
[INFO] running `"docker" "start" "-a" "0c6b59c11d50cb0a452fb9a32cdefc37ed23a7df40f11063de7b307d864f7959"`
[INFO] [stderr]    Compiling piston-float v0.2.0
[INFO] [stderr]    Compiling bitflags v0.6.0
[INFO] [stderr]    Compiling shader_version v0.2.2
[INFO] [stderr]    Compiling piston-texture v0.4.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling read_color v0.1.0
[INFO] [stderr]    Compiling piston-shaders_graphics2d v0.2.1
[INFO] [stderr]    Compiling piston-shaders_graphics2d v0.1.0
[INFO] [stderr]    Compiling x11-dl v2.18.4
[INFO] [stderr]    Compiling freetype-sys v0.3.1
[INFO] [stderr]    Compiling draw_state v0.4.0
[INFO] [stderr]    Compiling gif v0.8.0
[INFO] [stderr]    Compiling stb_truetype v0.3.0
[INFO] [stderr]    Compiling osmesa-sys v0.1.2
[INFO] [stderr]    Compiling gl_generator v0.5.5
[INFO] [stderr]    Compiling flate2 v0.2.20
[INFO] [stderr]    Compiling wayland-client v0.5.12
[INFO] [stderr]    Compiling num-bigint v0.1.44
[INFO] [stderr]    Compiling uuid v0.1.18
[INFO] [stderr]    Compiling draw_state v0.6.0
[INFO] [stderr]    Compiling piston-viewport v0.2.0
[INFO] [stderr]    Compiling vecmath v0.2.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.2
[INFO] [stderr]    Compiling hex2d v0.1.0
[INFO] [stderr]    Compiling target_build_utils v0.3.1
[INFO] [stderr]    Compiling pistoncore-input v0.12.0
[INFO] [stderr]    Compiling gfx_core v0.2.1
[INFO] [stderr]    Compiling stb_truetype v0.2.8
[INFO] [stderr]    Compiling freetype-rs v0.7.0
[INFO] [stderr]    Compiling gfx_core v0.3.1
[INFO] [stderr]    Compiling piston2d-graphics v0.16.0
[INFO] [stderr]    Compiling png v0.5.2
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling rusttype v0.2.4
[INFO] [stderr]    Compiling num-rational v0.1.42
[INFO] [stderr]    Compiling rayon-core v1.6.0
[INFO] [stderr]    Compiling gfx_gl v0.3.1
[INFO] [stderr]    Compiling glutin v0.5.2
[INFO] [stderr]    Compiling pistoncore-window v0.19.0
[INFO] [stderr]    Compiling piston-ai_behavior v0.14.0
[INFO] [stderr]    Compiling pistoncore-event_loop v0.22.1
[INFO] [stderr]    Compiling rayon v1.2.0
[INFO] [stderr]    Compiling piston2d-sprite v0.26.0
[INFO] [stderr]    Compiling piston v0.22.1
[INFO] [stderr]    Compiling jpeg-decoder v0.1.16
[INFO] [stderr]    Compiling libloading v0.3.4
[INFO] [stderr]    Compiling image v0.9.1
[INFO] [stderr]    Compiling dlib v0.3.1
[INFO] [stderr]    Compiling wayland-sys v0.5.11
[INFO] [stderr]    Compiling gfx v0.10.2
[INFO] [stderr]    Compiling gfx_device_gl v0.9.0
[INFO] [stderr]    Compiling piston2d-opengl_graphics v0.28.2
[INFO] [stderr]    Compiling wayland-kbd v0.3.6
[INFO] [stderr]    Compiling wayland-window v0.2.3
[INFO] [stderr]    Compiling piston-gfx_texture v0.14.0
[INFO] [stderr]    Compiling gfx_device_gl v0.10.0
[INFO] [stderr]    Compiling piston2d-gfx_graphics v0.27.0
[INFO] [stderr]    Compiling pistoncore-glutin_window v0.26.1
[INFO] [stderr]    Compiling piston_window v0.45.0
[INFO] [stderr]    Compiling board_v2 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(append)]
[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 `board_v2`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0c6b59c11d50cb0a452fb9a32cdefc37ed23a7df40f11063de7b307d864f7959"`
[INFO] running `"docker" "rm" "-f" "0c6b59c11d50cb0a452fb9a32cdefc37ed23a7df40f11063de7b307d864f7959"`
[INFO] [stdout] 0c6b59c11d50cb0a452fb9a32cdefc37ed23a7df40f11063de7b307d864f7959