[INFO] updating cached repository piggybox/blog_os
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/piggybox/blog_os
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/piggybox/blog_os" "work/ex/beta-1.38-1/sources/1.37.0/gh/piggybox/blog_os"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/piggybox/blog_os'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/piggybox/blog_os" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/piggybox/blog_os"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/piggybox/blog_os'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] cf61a2052fb42e60c91751f6baddf976cb55e44a
[INFO] sha for GitHub repo piggybox/blog_os: cf61a2052fb42e60c91751f6baddf976cb55e44a
[INFO] validating manifest of piggybox/blog_os 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 piggybox/blog_os 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 piggybox/blog_os
[INFO] finished frobbing piggybox/blog_os
[INFO] frobbed toml for piggybox/blog_os written to work/ex/beta-1.38-1/sources/1.37.0/gh/piggybox/blog_os/Cargo.toml
[INFO] started frobbing piggybox/blog_os
[INFO] finished frobbing piggybox/blog_os
[INFO] frobbed toml for piggybox/blog_os written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/piggybox/blog_os/Cargo.toml
[INFO] crate piggybox/blog_os 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing piggybox/blog_os 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-7/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/piggybox/blog_os:/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] aff74324b1bbc086b9c19dc47c2c2e54c42333dd048d4de3c9aae57c1dffce89
[INFO] running `"docker" "start" "-a" "aff74324b1bbc086b9c19dc47c2c2e54c42333dd048d4de3c9aae57c1dffce89"`
[INFO] [stderr]    Compiling blog_os v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0557]: feature has been removed
[INFO] [stderr]  --> src/main.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(panic_implementation)] // required for defining the panic handler
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr] note: subsumed by `#[panic_handler]`
[INFO] [stderr]  --> src/main.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(panic_implementation)] // required for defining the panic handler
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: cannot find attribute macro `panic_implementation` in this scope
[INFO] [stderr]  --> src/main.rs:8:3
[INFO] [stderr]   |
[INFO] [stderr] 8 | #[panic_implementation]
[INFO] [stderr]   |   ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(panic_implementation)] // required for defining the panic handler
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: `#[panic_handler]` function required, but not found
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0557.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `blog_os`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "aff74324b1bbc086b9c19dc47c2c2e54c42333dd048d4de3c9aae57c1dffce89"`
[INFO] running `"docker" "rm" "-f" "aff74324b1bbc086b9c19dc47c2c2e54c42333dd048d4de3c9aae57c1dffce89"`
[INFO] [stdout] aff74324b1bbc086b9c19dc47c2c2e54c42333dd048d4de3c9aae57c1dffce89