[INFO] crate gen-iter 0.1.2 is already in cache
[INFO] extracting crate gen-iter 0.1.2 into work/ex/beta-1.38-1/sources/1.37.0/reg/gen-iter/0.1.2
[INFO] extracting crate gen-iter 0.1.2 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/gen-iter/0.1.2
[INFO] validating manifest of gen-iter-0.1.2 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 gen-iter-0.1.2 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 gen-iter-0.1.2
[INFO] finished frobbing gen-iter-0.1.2
[INFO] frobbed toml for gen-iter-0.1.2 written to work/ex/beta-1.38-1/sources/1.37.0/reg/gen-iter/0.1.2/Cargo.toml
[INFO] started frobbing gen-iter-0.1.2
[INFO] finished frobbing gen-iter-0.1.2
[INFO] frobbed toml for gen-iter-0.1.2 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/gen-iter/0.1.2/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing gen-iter-0.1.2 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-6/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/gen-iter/0.1.2:/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] c4950d37f8151d1021979863f62f0e3f3de495d840de7b2e02f31f64d2b5a5f3
[INFO] running `"docker" "start" "-a" "c4950d37f8151d1021979863f62f0e3f3de495d840de7b2e02f31f64d2b5a5f3"`
[INFO] [stderr]    Compiling gen-iter v0.1.2 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> src/lib.rs:37:1
[INFO] [stderr]    |
[INFO] [stderr] 37 | #![feature(generators, generator_trait)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `resume` found for type `T` in the current scope
[INFO] [stderr]   --> src/lib.rs:53:22
[INFO] [stderr]    |
[INFO] [stderr] 53 |         match self.0.resume() {
[INFO] [stderr]    |                      ^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: items from traits can only be used if the type parameter is bounded by the trait
[INFO] [stderr] help: the following trait defines an item `resume`, perhaps you need to restrict type parameter `T` with it:
[INFO] [stderr]    |
[INFO] [stderr] 49 | impl<T: std::ops::Generator + Generator> Iterator for GenIter<T> {
[INFO] [stderr]    |      ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `gen-iter`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "c4950d37f8151d1021979863f62f0e3f3de495d840de7b2e02f31f64d2b5a5f3"`
[INFO] running `"docker" "rm" "-f" "c4950d37f8151d1021979863f62f0e3f3de495d840de7b2e02f31f64d2b5a5f3"`
[INFO] [stdout] c4950d37f8151d1021979863f62f0e3f3de495d840de7b2e02f31f64d2b5a5f3