[INFO] updating cached repository lights0123/n-flashcards
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/lights0123/n-flashcards
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/lights0123/n-flashcards" "work/ex/beta-1.38-1/sources/1.37.0/gh/lights0123/n-flashcards"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/lights0123/n-flashcards'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/lights0123/n-flashcards" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/lights0123/n-flashcards"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/lights0123/n-flashcards'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 02f89be2aaad202bdb4641ae47b2d9bb75b19748
[INFO] sha for GitHub repo lights0123/n-flashcards: 02f89be2aaad202bdb4641ae47b2d9bb75b19748
[INFO] validating manifest of lights0123/n-flashcards 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 lights0123/n-flashcards 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 lights0123/n-flashcards
[INFO] finished frobbing lights0123/n-flashcards
[INFO] frobbed toml for lights0123/n-flashcards written to work/ex/beta-1.38-1/sources/1.37.0/gh/lights0123/n-flashcards/Cargo.toml
[INFO] started frobbing lights0123/n-flashcards
[INFO] finished frobbing lights0123/n-flashcards
[INFO] frobbed toml for lights0123/n-flashcards written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/lights0123/n-flashcards/Cargo.toml
[INFO] crate lights0123/n-flashcards 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 lights0123/n-flashcards 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/lights0123/n-flashcards:/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] 9cb30bc888a58a3b918340a434802adb5f220a1d174a26477ad3196bc68ad849
[INFO] running `"docker" "start" "-a" "9cb30bc888a58a3b918340a434802adb5f220a1d174a26477ad3196bc68ad849"`
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]    Compiling num-iter v0.1.37
[INFO] [stderr]    Compiling cty v0.2.0
[INFO] [stderr]    Compiling cty v0.1.5
[INFO] [stderr]    Compiling num-complex v0.2.1
[INFO] [stderr]    Compiling ndless-static-vars v1.0.0
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling spin v0.5.0
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr] error[E0412]: cannot find type `Vec` in this scope
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/ndless-static-vars-1.0.0/src/lib.rs:7:34
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub static mut ARGUMENTS: Option<Vec<String>> = None;
[INFO] [stderr]   |                                  ^^^ not found in this scope
[INFO] [stderr] help: possible candidates are found in other modules, you can import them into scope
[INFO] [stderr]   |
[INFO] [stderr] 5 | use alloc::prelude::v1::Vec;
[INFO] [stderr]   |
[INFO] [stderr] 5 | use alloc::vec::Vec;
[INFO] [stderr]   |
[INFO] [stderr] 
[INFO] [stderr] error[E0412]: cannot find type `String` in this scope
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/ndless-static-vars-1.0.0/src/lib.rs:7:38
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub static mut ARGUMENTS: Option<Vec<String>> = None;
[INFO] [stderr]   |                                      ^^^^^^ not found in this scope
[INFO] [stderr] help: possible candidates are found in other modules, you can import them into scope
[INFO] [stderr]   |
[INFO] [stderr] 5 | use alloc::prelude::v1::String;
[INFO] [stderr]   |
[INFO] [stderr] 5 | use alloc::string::String;
[INFO] [stderr]   |
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/ndless-static-vars-1.0.0/src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(alloc)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'alloc_prelude'
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/ndless-static-vars-1.0.0/src/lib.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use alloc::prelude::*;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: for more information, see https://github.com/rust-lang/rust/issues/58935
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0412, E0554, E0658.
[INFO] [stderr] For more information about an error, try `rustc --explain E0412`.
[INFO] [stderr] error: Could not compile `ndless-static-vars`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "9cb30bc888a58a3b918340a434802adb5f220a1d174a26477ad3196bc68ad849"`
[INFO] running `"docker" "rm" "-f" "9cb30bc888a58a3b918340a434802adb5f220a1d174a26477ad3196bc68ad849"`
[INFO] [stdout] 9cb30bc888a58a3b918340a434802adb5f220a1d174a26477ad3196bc68ad849