[INFO] updating cached repository DanielKeep/calendar-example
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/DanielKeep/calendar-example
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/DanielKeep/calendar-example" "work/ex/beta-1.38-1/sources/1.37.0/gh/DanielKeep/calendar-example"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/DanielKeep/calendar-example'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/DanielKeep/calendar-example" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/DanielKeep/calendar-example"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/DanielKeep/calendar-example'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 399f1b0fafac49df5e52a57b350a9c8b09ea046b
[INFO] sha for GitHub repo DanielKeep/calendar-example: 399f1b0fafac49df5e52a57b350a9c8b09ea046b
[INFO] validating manifest of DanielKeep/calendar-example 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 DanielKeep/calendar-example 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 DanielKeep/calendar-example
[INFO] finished frobbing DanielKeep/calendar-example
[INFO] frobbed toml for DanielKeep/calendar-example written to work/ex/beta-1.38-1/sources/1.37.0/gh/DanielKeep/calendar-example/Cargo.toml
[INFO] started frobbing DanielKeep/calendar-example
[INFO] finished frobbing DanielKeep/calendar-example
[INFO] frobbed toml for DanielKeep/calendar-example written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/DanielKeep/calendar-example/Cargo.toml
[INFO] crate DanielKeep/calendar-example 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 DanielKeep/calendar-example 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/DanielKeep/calendar-example:/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] 0738ace3259b3607b52b5ff970d65754e96c411ddc06458346edff502f14a5c6
[INFO] running `"docker" "start" "-a" "0738ace3259b3607b52b5ff970d65754e96c411ddc06458346edff502f14a5c6"`
[INFO] [stderr]    Compiling num-traits v0.1.34
[INFO] [stderr]    Compiling itertools v0.4.17
[INFO] [stderr]    Compiling num-integer v0.1.32
[INFO] [stderr]    Compiling num-iter v0.1.32
[INFO] [stderr]    Compiling num v0.1.34
[INFO] [stderr]    Compiling chrono v0.2.25
[INFO] [stderr]    Compiling calendar v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> bin.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(conservative_impl_trait)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0562]: `impl Trait` not allowed outside of function and inherent method return types
[INFO] [stderr]    --> bin.rs:386:23
[INFO] [stderr]     |
[INFO] [stderr] 386 | -> impl FnOnce(It) -> impl Iterator<Item=String>
[INFO] [stderr]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0562]: `impl Trait` not allowed outside of function and inherent method return types
[INFO] [stderr]    --> bin.rs:456:57
[INFO] [stderr]     |
[INFO] [stderr] 456 | fn chunks<It: Iterator>(n: usize) -> impl FnOnce(It) -> impl Iterator<Item=Vec<It::Item>> {
[INFO] [stderr]     |                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0282]: type annotations needed
[INFO] [stderr]    --> bin.rs:506:15
[INFO] [stderr]     |
[INFO] [stderr] 506 |         .map(|r| r.into_iter()
[INFO] [stderr]     |               ^ consider giving this closure parameter a type
[INFO] [stderr]     |
[INFO] [stderr]     = note: type must be known at this point
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0282, E0554, E0562.
[INFO] [stderr] For more information about an error, try `rustc --explain E0282`.
[INFO] [stderr] error: Could not compile `calendar`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0738ace3259b3607b52b5ff970d65754e96c411ddc06458346edff502f14a5c6"`
[INFO] running `"docker" "rm" "-f" "0738ace3259b3607b52b5ff970d65754e96c411ddc06458346edff502f14a5c6"`
[INFO] [stdout] 0738ace3259b3607b52b5ff970d65754e96c411ddc06458346edff502f14a5c6