[INFO] updating cached repository https://github.com/jaroslaw-weber/rust-procedural-macros-examples
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 876a51061cb0d40f54f121215d545efd534ff202
[INFO] testing jaroslaw-weber/rust-procedural-macros-examples against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjaroslaw-weber%2Frust-procedural-macros-examples" "work/builds/worker-4/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jaroslaw-weber/rust-procedural-macros-examples on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/jaroslaw-weber/rust-procedural-macros-examples
[INFO] finished tweaking git repo https://github.com/jaroslaw-weber/rust-procedural-macros-examples
[INFO] tweaked toml for git repo https://github.com/jaroslaw-weber/rust-procedural-macros-examples written to work/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/jaroslaw-weber/rust-procedural-macros-examples already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 3c2d232c0ddb04c5cc4e327889c4d5106ed2531843a5e5256c9edd978e224a7e
[INFO] running `"docker" "start" "-a" "3c2d232c0ddb04c5cc4e327889c4d5106ed2531843a5e5256c9edd978e224a7e"`
[INFO] [stderr]    Compiling procedural_macros_simple_examples v0.1.0 (/opt/rustwide/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" "3c2d232c0ddb04c5cc4e327889c4d5106ed2531843a5e5256c9edd978e224a7e"`
[INFO] running `"docker" "rm" "-f" "3c2d232c0ddb04c5cc4e327889c4d5106ed2531843a5e5256c9edd978e224a7e"`
[INFO] [stdout] 3c2d232c0ddb04c5cc4e327889c4d5106ed2531843a5e5256c9edd978e224a7e