[INFO] updating cached repository charliethomson/arraylist
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/charliethomson/arraylist
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/charliethomson/arraylist" "work/ex/beta-1.38-1/sources/1.37.0/gh/charliethomson/arraylist"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/charliethomson/arraylist'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/charliethomson/arraylist" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/charliethomson/arraylist"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/charliethomson/arraylist'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b6d16fe34792c4c4bd6f956d94a9b3d57cc887ee
[INFO] sha for GitHub repo charliethomson/arraylist: b6d16fe34792c4c4bd6f956d94a9b3d57cc887ee
[INFO] validating manifest of charliethomson/arraylist 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 charliethomson/arraylist 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 charliethomson/arraylist
[INFO] finished frobbing charliethomson/arraylist
[INFO] frobbed toml for charliethomson/arraylist written to work/ex/beta-1.38-1/sources/1.37.0/gh/charliethomson/arraylist/Cargo.toml
[INFO] started frobbing charliethomson/arraylist
[INFO] finished frobbing charliethomson/arraylist
[INFO] frobbed toml for charliethomson/arraylist written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/charliethomson/arraylist/Cargo.toml
[INFO] crate charliethomson/arraylist 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 charliethomson/arraylist 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/charliethomson/arraylist:/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] f187e05eb2100b87159f8f9b63e3879ee2fcaa4f53c0aaf4477821c19f8fea25
[INFO] running `"docker" "start" "-a" "f187e05eb2100b87159f8f9b63e3879ee2fcaa4f53c0aaf4477821c19f8fea25"`
[INFO] [stderr]    Compiling dynamic_array 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:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(alloc_layout_extra)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[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 `dynamic_array`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "f187e05eb2100b87159f8f9b63e3879ee2fcaa4f53c0aaf4477821c19f8fea25"`
[INFO] running `"docker" "rm" "-f" "f187e05eb2100b87159f8f9b63e3879ee2fcaa4f53c0aaf4477821c19f8fea25"`
[INFO] [stdout] f187e05eb2100b87159f8f9b63e3879ee2fcaa4f53c0aaf4477821c19f8fea25