[INFO] updating cached repository Woyten/math-util
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Woyten/math-util
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Woyten/math-util" "work/ex/beta-1.38-1/sources/1.37.0/gh/Woyten/math-util"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Woyten/math-util'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Woyten/math-util" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Woyten/math-util"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Woyten/math-util'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] ac824440152248228880fd4b32ca5066bfb80077
[INFO] sha for GitHub repo Woyten/math-util: ac824440152248228880fd4b32ca5066bfb80077
[INFO] validating manifest of Woyten/math-util 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 Woyten/math-util 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 Woyten/math-util
[INFO] finished frobbing Woyten/math-util
[INFO] frobbed toml for Woyten/math-util written to work/ex/beta-1.38-1/sources/1.37.0/gh/Woyten/math-util/Cargo.toml
[INFO] started frobbing Woyten/math-util
[INFO] finished frobbing Woyten/math-util
[INFO] frobbed toml for Woyten/math-util written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Woyten/math-util/Cargo.toml
[INFO] crate Woyten/math-util 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 Woyten/math-util 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/Woyten/math-util:/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] ded3af919d8615418363e2a95160ed215bb5c9d98807b0259d25b443ff606a81
[INFO] running `"docker" "start" "-a" "ded3af919d8615418363e2a95160ed215bb5c9d98807b0259d25b443ff606a81"`
[INFO] [stderr]    Compiling num_cpus v1.7.0
[INFO] [stderr]    Compiling rand v0.5.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.3.1
[INFO] [stderr]    Compiling rustfft v2.1.0
[INFO] [stderr]    Compiling crossbeam-deque v0.2.0
[INFO] [stderr]    Compiling rayon-core v1.4.1
[INFO] [stderr]    Compiling rayon v1.0.3
[INFO] [stderr]    Compiling nalgebra v0.16.8
[INFO] [stderr] warning[E0502]: cannot borrow `*self` as immutable because it is also borrowed as mutable
[INFO] [stderr]    --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/nalgebra-0.16.8/src/base/cg.rs:291:44
[INFO] [stderr]     |
[INFO] [stderr] 291 |                 self[(j, i)] += shift[j] * self[(D::dim() - 1, i)];
[INFO] [stderr]     |                 ---------------------------^^^^-------------------
[INFO] [stderr]     |                 |                          |
[INFO] [stderr]     |                 |                          immutable borrow occurs here
[INFO] [stderr]     |                 mutable borrow occurs here
[INFO] [stderr]     |                 mutable borrow later used here
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]     = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]    Compiling math-util v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 48.44s
[INFO] running `"docker" "inspect" "ded3af919d8615418363e2a95160ed215bb5c9d98807b0259d25b443ff606a81"`
[INFO] running `"docker" "rm" "-f" "ded3af919d8615418363e2a95160ed215bb5c9d98807b0259d25b443ff606a81"`
[INFO] [stdout] ded3af919d8615418363e2a95160ed215bb5c9d98807b0259d25b443ff606a81
[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/Woyten/math-util:/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] d599de218766661f196d38cc5e26fb97a148ef92dc7df4e929a60ff3786e90a3
[INFO] running `"docker" "start" "-a" "d599de218766661f196d38cc5e26fb97a148ef92dc7df4e929a60ff3786e90a3"`
[INFO] [stderr]    Compiling math-util v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0432]: unresolved import `num`
[INFO] [stderr]  --> examples/benchmark.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use num::Complex;
[INFO] [stderr]   |     ^^^ help: a similar path exists: `std::num`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0432`.
[INFO] [stderr] error: Could not compile `math-util`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "d599de218766661f196d38cc5e26fb97a148ef92dc7df4e929a60ff3786e90a3"`
[INFO] running `"docker" "rm" "-f" "d599de218766661f196d38cc5e26fb97a148ef92dc7df4e929a60ff3786e90a3"`
[INFO] [stdout] d599de218766661f196d38cc5e26fb97a148ef92dc7df4e929a60ff3786e90a3