[INFO] updating cached repository bivory/pi-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/bivory/pi-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/bivory/pi-rust" "work/ex/beta-1.38-1/sources/1.37.0/gh/bivory/pi-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/bivory/pi-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/bivory/pi-rust" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bivory/pi-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bivory/pi-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a9ae3c022748557d9217e86ce3ce8601a19a9bd9
[INFO] sha for GitHub repo bivory/pi-rust: a9ae3c022748557d9217e86ce3ce8601a19a9bd9
[INFO] validating manifest of bivory/pi-rust 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 bivory/pi-rust 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 bivory/pi-rust
[INFO] finished frobbing bivory/pi-rust
[INFO] frobbed toml for bivory/pi-rust written to work/ex/beta-1.38-1/sources/1.37.0/gh/bivory/pi-rust/Cargo.toml
[INFO] started frobbing bivory/pi-rust
[INFO] finished frobbing bivory/pi-rust
[INFO] frobbed toml for bivory/pi-rust written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bivory/pi-rust/Cargo.toml
[INFO] crate bivory/pi-rust 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/bivory/pi-rust/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[INFO] the lockfile is outdated, regenerating it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] 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 bivory/pi-rust 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-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/bivory/pi-rust:/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] e1c228550e19e10c9a9be6e81a655ba74903c744e4a2235316525fcbaf071448
[INFO] running `"docker" "start" "-a" "e1c228550e19e10c9a9be6e81a655ba74903c744e4a2235316525fcbaf071448"`
[INFO] [stderr]    Compiling pi v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` head expression
[INFO] [stderr]   --> src/main.rs:22:14
[INFO] [stderr]    |
[INFO] [stderr] 22 |     for _ in (0..samples)
[INFO] [stderr]    |              ^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_parens)] 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 `pi`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "e1c228550e19e10c9a9be6e81a655ba74903c744e4a2235316525fcbaf071448"`
[INFO] running `"docker" "rm" "-f" "e1c228550e19e10c9a9be6e81a655ba74903c744e4a2235316525fcbaf071448"`
[INFO] [stdout] e1c228550e19e10c9a9be6e81a655ba74903c744e4a2235316525fcbaf071448