[INFO] updating cached repository zjhken/MioPractice
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/zjhken/MioPractice
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/zjhken/MioPractice" "work/ex/beta-1.38-1/sources/1.37.0/gh/zjhken/MioPractice"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/zjhken/MioPractice'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/zjhken/MioPractice" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/zjhken/MioPractice"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/zjhken/MioPractice'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b7e077633c9c64e7342ee2e473eea1a4421e8a49
[INFO] sha for GitHub repo zjhken/MioPractice: b7e077633c9c64e7342ee2e473eea1a4421e8a49
[INFO] validating manifest of zjhken/MioPractice 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 zjhken/MioPractice 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 zjhken/MioPractice
[INFO] finished frobbing zjhken/MioPractice
[INFO] frobbed toml for zjhken/MioPractice written to work/ex/beta-1.38-1/sources/1.37.0/gh/zjhken/MioPractice/Cargo.toml
[INFO] started frobbing zjhken/MioPractice
[INFO] finished frobbing zjhken/MioPractice
[INFO] frobbed toml for zjhken/MioPractice written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/zjhken/MioPractice/Cargo.toml
[INFO] crate zjhken/MioPractice 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 zjhken/MioPractice 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-2/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/zjhken/MioPractice:/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] e8e362197e844e2fdd0a4f06f39f11b4e69d0a2328516d3cffd91e8d601f43f4
[INFO] running `"docker" "start" "-a" "e8e362197e844e2fdd0a4f06f39f11b4e69d0a2328516d3cffd91e8d601f43f4"`
[INFO] [stderr]    Compiling libc v0.2.42
[INFO] [stderr]    Compiling slab v0.4.0
[INFO] [stderr]    Compiling lazycell v0.6.0
[INFO] [stderr]    Compiling log v0.4.4
[INFO] [stderr]    Compiling time v0.1.40
[INFO] [stderr]    Compiling net2 v0.2.32
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling mio v0.6.14
[INFO] [stderr]    Compiling simple_logger v0.5.0
[INFO] [stderr]    Compiling MioPractice 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:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(nll)]
[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 `MioPractice`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "e8e362197e844e2fdd0a4f06f39f11b4e69d0a2328516d3cffd91e8d601f43f4"`
[INFO] running `"docker" "rm" "-f" "e8e362197e844e2fdd0a4f06f39f11b4e69d0a2328516d3cffd91e8d601f43f4"`
[INFO] [stdout] e8e362197e844e2fdd0a4f06f39f11b4e69d0a2328516d3cffd91e8d601f43f4