[INFO] updating cached repository jaroslaw-weber/rust-procedural-macros-examples
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/jaroslaw-weber/rust-procedural-macros-examples
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/jaroslaw-weber/rust-procedural-macros-examples" "work/ex/beta-1.38-1/sources/1.37.0/gh/jaroslaw-weber/rust-procedural-macros-examples"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/jaroslaw-weber/rust-procedural-macros-examples'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/jaroslaw-weber/rust-procedural-macros-examples" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jaroslaw-weber/rust-procedural-macros-examples"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jaroslaw-weber/rust-procedural-macros-examples'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 876a51061cb0d40f54f121215d545efd534ff202
[INFO] sha for GitHub repo jaroslaw-weber/rust-procedural-macros-examples: 876a51061cb0d40f54f121215d545efd534ff202
[INFO] validating manifest of jaroslaw-weber/rust-procedural-macros-examples 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 jaroslaw-weber/rust-procedural-macros-examples 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 jaroslaw-weber/rust-procedural-macros-examples
[INFO] finished frobbing jaroslaw-weber/rust-procedural-macros-examples
[INFO] frobbed toml for jaroslaw-weber/rust-procedural-macros-examples written to work/ex/beta-1.38-1/sources/1.37.0/gh/jaroslaw-weber/rust-procedural-macros-examples/Cargo.toml
[INFO] started frobbing jaroslaw-weber/rust-procedural-macros-examples
[INFO] finished frobbing jaroslaw-weber/rust-procedural-macros-examples
[INFO] frobbed toml for jaroslaw-weber/rust-procedural-macros-examples written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jaroslaw-weber/rust-procedural-macros-examples/Cargo.toml
[INFO] crate jaroslaw-weber/rust-procedural-macros-examples 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 jaroslaw-weber/rust-procedural-macros-examples 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-2/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/jaroslaw-weber/rust-procedural-macros-examples:/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] 66f6454ecbf18b767d7980522627c8eba15099a8760bacf43ac1e21a7db04603
[INFO] running `"docker" "start" "-a" "66f6454ecbf18b767d7980522627c8eba15099a8760bacf43ac1e21a7db04603"`
[INFO] [stderr]    Compiling procedural_macros_simple_examples v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(proc_macro)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/roman_parser.rs:21:53
[INFO] [stderr]    |
[INFO] [stderr] 21 | pub fn roman_to_i32(input: &str) -> Result<i32, Box<Error>> {
[INFO] [stderr]    |                                                     ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(bare_trait_objects)] on by default
[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 `procedural_macros_simple_examples`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "66f6454ecbf18b767d7980522627c8eba15099a8760bacf43ac1e21a7db04603"`
[INFO] running `"docker" "rm" "-f" "66f6454ecbf18b767d7980522627c8eba15099a8760bacf43ac1e21a7db04603"`
[INFO] [stdout] 66f6454ecbf18b767d7980522627c8eba15099a8760bacf43ac1e21a7db04603