[INFO] updating cached repository scottschroeder/caesar
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/scottschroeder/caesar
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/scottschroeder/caesar" "work/ex/beta-1.38-1/sources/1.37.0/gh/scottschroeder/caesar"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/scottschroeder/caesar'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/scottschroeder/caesar" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/scottschroeder/caesar"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/scottschroeder/caesar'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] ca51a1018356e1ee51a3ca48744d2a70621ee1a2
[INFO] sha for GitHub repo scottschroeder/caesar: ca51a1018356e1ee51a3ca48744d2a70621ee1a2
[INFO] validating manifest of scottschroeder/caesar 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 scottschroeder/caesar 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 scottschroeder/caesar
[INFO] finished frobbing scottschroeder/caesar
[INFO] frobbed toml for scottschroeder/caesar written to work/ex/beta-1.38-1/sources/1.37.0/gh/scottschroeder/caesar/Cargo.toml
[INFO] started frobbing scottschroeder/caesar
[INFO] finished frobbing scottschroeder/caesar
[INFO] frobbed toml for scottschroeder/caesar written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/scottschroeder/caesar/Cargo.toml
[INFO] crate scottschroeder/caesar 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] [stderr] error: the lock file /mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/scottschroeder/caesar/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[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] 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 scottschroeder/caesar 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-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/scottschroeder/caesar:/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] 422c63ae47236640fedd947c4a4b401de651ff519009859acf0e1fb8a3b0d5c9
[INFO] running `"docker" "start" "-a" "422c63ae47236640fedd947c4a4b401de651ff519009859acf0e1fb8a3b0d5c9"`
[INFO] [stderr]    Compiling itertools v0.4.19
[INFO] [stderr]    Compiling caesar v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(box_syntax)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/shifty/error.rs:38:32
[INFO] [stderr]    |
[INFO] [stderr] 38 |     fn cause(&self) -> Option<&error::Error> {
[INFO] [stderr]    |                                ^^^^^^^^^^^^ help: use `dyn`: `dyn error::Error`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(bare_trait_objects)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/shifty/error.rs:75:32
[INFO] [stderr]    |
[INFO] [stderr] 75 |     fn cause(&self) -> Option<&error::Error> {
[INFO] [stderr]    |                                ^^^^^^^^^^^^ help: use `dyn`: `dyn error::Error`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/main.rs:19:49
[INFO] [stderr]    |
[INFO] [stderr] 19 | pub type Result<T> = std::result::Result<T, Box<error::Error>>;
[INFO] [stderr]    |                                                 ^^^^^^^^^^^^ help: use `dyn`: `dyn error::Error`
[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 `caesar`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "422c63ae47236640fedd947c4a4b401de651ff519009859acf0e1fb8a3b0d5c9"`
[INFO] running `"docker" "rm" "-f" "422c63ae47236640fedd947c4a4b401de651ff519009859acf0e1fb8a3b0d5c9"`
[INFO] [stdout] 422c63ae47236640fedd947c4a4b401de651ff519009859acf0e1fb8a3b0d5c9