[INFO] updating cached repository andrewdavidmackenzie/mandelbrot
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/andrewdavidmackenzie/mandelbrot
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/andrewdavidmackenzie/mandelbrot" "work/ex/beta-1.38-1/sources/1.37.0/gh/andrewdavidmackenzie/mandelbrot"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/andrewdavidmackenzie/mandelbrot'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/andrewdavidmackenzie/mandelbrot" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/andrewdavidmackenzie/mandelbrot"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/andrewdavidmackenzie/mandelbrot'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 156ccacdb66c2dfb48603bc1ba1b82e17ce07059
[INFO] sha for GitHub repo andrewdavidmackenzie/mandelbrot: 156ccacdb66c2dfb48603bc1ba1b82e17ce07059
[INFO] validating manifest of andrewdavidmackenzie/mandelbrot 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 andrewdavidmackenzie/mandelbrot 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 andrewdavidmackenzie/mandelbrot
[INFO] finished frobbing andrewdavidmackenzie/mandelbrot
[INFO] frobbed toml for andrewdavidmackenzie/mandelbrot written to work/ex/beta-1.38-1/sources/1.37.0/gh/andrewdavidmackenzie/mandelbrot/Cargo.toml
[INFO] started frobbing andrewdavidmackenzie/mandelbrot
[INFO] finished frobbing andrewdavidmackenzie/mandelbrot
[INFO] frobbed toml for andrewdavidmackenzie/mandelbrot written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/andrewdavidmackenzie/mandelbrot/Cargo.toml
[INFO] crate andrewdavidmackenzie/mandelbrot 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 andrewdavidmackenzie/mandelbrot 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-4/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/andrewdavidmackenzie/mandelbrot:/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] 167a9fbe9b6f70d325b67fbfaf8e589aafb92bc49d0e7a82a87316b0fc8fba15
[INFO] running `"docker" "start" "-a" "167a9fbe9b6f70d325b67fbfaf8e589aafb92bc49d0e7a82a87316b0fc8fba15"`
[INFO] [stderr]    Compiling cc v1.0.3
[INFO] [stderr]    Compiling libc v0.2.33
[INFO] [stderr]    Compiling num-traits v0.1.40
[INFO] [stderr]    Compiling rustc-serialize v0.3.24
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling either v1.4.0
[INFO] [stderr]    Compiling rayon-core v1.3.0
[INFO] [stderr]    Compiling lzw v0.9.0
[INFO] [stderr]    Compiling color_quant v1.0.0
[INFO] [stderr]    Compiling same-file v0.1.3
[INFO] [stderr]    Compiling inflate v0.1.1
[INFO] [stderr]    Compiling bitflags v0.3.3
[INFO] [stderr]    Compiling byteorder v0.4.2
[INFO] [stderr]    Compiling glob v0.2.11
[INFO] [stderr]    Compiling coco v0.1.1
[INFO] [stderr]    Compiling walkdir v1.0.7
[INFO] [stderr]    Compiling rand v0.3.18
[INFO] [stderr]    Compiling num_cpus v1.7.0
[INFO] [stderr]    Compiling gif v0.7.0
[INFO] [stderr]    Compiling num-integer v0.1.35
[INFO] [stderr]    Compiling enum_primitive v0.1.1
[INFO] [stderr]    Compiling dir-diff v0.2.0
[INFO] [stderr]    Compiling num-iter v0.1.34
[INFO] [stderr]    Compiling tempdir v0.3.5
[INFO] [stderr]    Compiling miniz-sys v0.1.10
[INFO] [stderr]    Compiling rayon v0.9.0
[INFO] [stderr]    Compiling flate2 v0.2.20
[INFO] [stderr]    Compiling num-bigint v0.1.40
[INFO] [stderr]    Compiling num-complex v0.1.40
[INFO] [stderr]    Compiling png v0.4.3
[INFO] [stderr]    Compiling num-rational v0.1.40
[INFO] [stderr]    Compiling num v0.1.40
[INFO] [stderr]    Compiling image v0.6.1
[INFO] [stderr]    Compiling mandlebrot v3.1.0 (/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: 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 `mandlebrot`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "167a9fbe9b6f70d325b67fbfaf8e589aafb92bc49d0e7a82a87316b0fc8fba15"`
[INFO] running `"docker" "rm" "-f" "167a9fbe9b6f70d325b67fbfaf8e589aafb92bc49d0e7a82a87316b0fc8fba15"`
[INFO] [stdout] 167a9fbe9b6f70d325b67fbfaf8e589aafb92bc49d0e7a82a87316b0fc8fba15