[INFO] updating cached repository statianzo/imposters
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/statianzo/imposters
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/statianzo/imposters" "work/ex/beta-1.38-1/sources/1.37.0/gh/statianzo/imposters"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/statianzo/imposters'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/statianzo/imposters" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/statianzo/imposters"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/statianzo/imposters'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 344a5027ba57464a424c1906376445b6e208cb57
[INFO] sha for GitHub repo statianzo/imposters: 344a5027ba57464a424c1906376445b6e208cb57
[INFO] validating manifest of statianzo/imposters 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 statianzo/imposters 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 statianzo/imposters
[INFO] finished frobbing statianzo/imposters
[INFO] frobbed toml for statianzo/imposters written to work/ex/beta-1.38-1/sources/1.37.0/gh/statianzo/imposters/Cargo.toml
[INFO] started frobbing statianzo/imposters
[INFO] finished frobbing statianzo/imposters
[INFO] frobbed toml for statianzo/imposters written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/statianzo/imposters/Cargo.toml
[INFO] crate statianzo/imposters 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 statianzo/imposters 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-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/statianzo/imposters:/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] 97aa16b43cbd307a684a678d8ba28e5df80de717c42bc7467acad5d80986a6d8
[INFO] running `"docker" "start" "-a" "97aa16b43cbd307a684a678d8ba28e5df80de717c42bc7467acad5d80986a6d8"`
[INFO] [stderr]    Compiling imposters v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.80s
[INFO] running `"docker" "inspect" "97aa16b43cbd307a684a678d8ba28e5df80de717c42bc7467acad5d80986a6d8"`
[INFO] running `"docker" "rm" "-f" "97aa16b43cbd307a684a678d8ba28e5df80de717c42bc7467acad5d80986a6d8"`
[INFO] [stdout] 97aa16b43cbd307a684a678d8ba28e5df80de717c42bc7467acad5d80986a6d8
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/statianzo/imposters:/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] 0876571257ae9de8af313fded4cbbcfed5259f026651a7f19fcf149dad08476f
[INFO] running `"docker" "start" "-a" "0876571257ae9de8af313fded4cbbcfed5259f026651a7f19fcf149dad08476f"`
[INFO] [stderr]    Compiling regex v1.0.1
[INFO] [stderr]    Compiling env_logger v0.5.10
[INFO] [stderr]    Compiling quickcheck v0.6.2
[INFO] [stderr]    Compiling imposters v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:19
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![cfg_attr(test, 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 `imposters`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0876571257ae9de8af313fded4cbbcfed5259f026651a7f19fcf149dad08476f"`
[INFO] running `"docker" "rm" "-f" "0876571257ae9de8af313fded4cbbcfed5259f026651a7f19fcf149dad08476f"`
[INFO] [stdout] 0876571257ae9de8af313fded4cbbcfed5259f026651a7f19fcf149dad08476f