[INFO] updating cached repository jkuczm/tree_cache
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/jkuczm/tree_cache
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/jkuczm/tree_cache" "work/ex/beta-1.38-1/sources/1.37.0/gh/jkuczm/tree_cache"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/jkuczm/tree_cache'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/jkuczm/tree_cache" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jkuczm/tree_cache"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jkuczm/tree_cache'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9927b0a0a8c4928625afa1d6f12175975563d80c
[INFO] sha for GitHub repo jkuczm/tree_cache: 9927b0a0a8c4928625afa1d6f12175975563d80c
[INFO] validating manifest of jkuczm/tree_cache 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 jkuczm/tree_cache 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 jkuczm/tree_cache
[INFO] finished frobbing jkuczm/tree_cache
[INFO] frobbed toml for jkuczm/tree_cache written to work/ex/beta-1.38-1/sources/1.37.0/gh/jkuczm/tree_cache/Cargo.toml
[INFO] started frobbing jkuczm/tree_cache
[INFO] finished frobbing jkuczm/tree_cache
[INFO] frobbed toml for jkuczm/tree_cache written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jkuczm/tree_cache/Cargo.toml
[INFO] crate jkuczm/tree_cache 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 jkuczm/tree_cache against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-5/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jkuczm/tree_cache:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] b57000be681d36ac5ec95100ad2d680570e87af4ad8c77d796fb9b6dd153a1d6
[INFO] running `"docker" "start" "-a" "b57000be681d36ac5ec95100ad2d680570e87af4ad8c77d796fb9b6dd153a1d6"`
[INFO] [stderr]    Compiling cc v1.0.29
[INFO] [stderr]    Compiling memchr v2.1.3
[INFO] [stderr]    Compiling serde v1.0.87
[INFO] [stderr]    Compiling rustc-demangle v0.1.13
[INFO] [stderr]    Compiling crunchy v0.2.1
[INFO] [stderr]    Compiling rustc-hex v2.0.1
[INFO] [stderr]    Compiling array-macro v1.0.3
[INFO] [stderr]    Compiling backtrace v0.3.13
[INFO] [stderr]    Compiling bincode v1.1.1
[INFO] [stderr]    Compiling syn v0.15.26
[INFO] [stderr]    Compiling rayon-core v1.4.1
[INFO] [stderr]    Compiling uint v0.6.1
[INFO] [stderr]    Compiling rayon v1.0.3
[INFO] [stderr]    Compiling aho-corasick v0.6.9
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]    Compiling env_logger v0.5.13
[INFO] [stderr]    Compiling synstructure v0.10.1
[INFO] [stderr]    Compiling structopt-derive v0.2.15
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling serde_derive v1.0.87
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling exitfailure v0.5.1
[INFO] [stderr]    Compiling structopt v0.2.15
[INFO] [stderr]    Compiling clap-verbosity-flag v0.2.0
[INFO] [stderr]    Compiling tree_cache v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | / #![feature(
[INFO] [stderr] 2 | |     vec_resize_default, step_trait, associated_type_defaults, result_map_or_else,
[INFO] [stderr] 3 | |     proc_macro_hygiene
[INFO] [stderr] 4 | | )]
[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 `tree_cache`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "b57000be681d36ac5ec95100ad2d680570e87af4ad8c77d796fb9b6dd153a1d6"`
[INFO] running `"docker" "rm" "-f" "b57000be681d36ac5ec95100ad2d680570e87af4ad8c77d796fb9b6dd153a1d6"`
[INFO] [stdout] b57000be681d36ac5ec95100ad2d680570e87af4ad8c77d796fb9b6dd153a1d6