[INFO] crate rmcmc 0.1.0 is already in cache
[INFO] testing rmcmc-0.1.0 against 1.38.0 for beta-1.39-1
[INFO] extracting crate rmcmc 0.1.0 into work/builds/worker-2/source
[INFO] validating manifest of crates.io crate rmcmc 0.1.0 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 crates.io crate rmcmc 0.1.0
[INFO] finished tweaking crates.io crate rmcmc 0.1.0
[INFO] tweaked toml for crates.io crate rmcmc 0.1.0 written to work/builds/worker-2/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-2/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-2/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] 3f7126af673c683bd0439f52b77a735069519fe8927df98efc4755b977cf7754
[INFO] running `"docker" "start" "-a" "3f7126af673c683bd0439f52b77a735069519fe8927df98efc4755b977cf7754"`
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling num-bigint v0.2.3
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling generic-array v0.11.1
[INFO] [stderr]    Compiling special v0.7.8
[INFO] [stderr]    Compiling approx v0.3.2
[INFO] [stderr]    Compiling alga v0.7.2
[INFO] [stderr]    Compiling num v0.2.0
[INFO] [stderr]    Compiling nalgebra v0.16.14
[INFO] [stderr]    Compiling rv v0.4.1
[INFO] [stderr] warning[E0502]: cannot borrow `summed` as immutable because it is also borrowed as mutable
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/rv-0.4.1/src/misc/func.rs:55:22
[INFO] [stderr]    |
[INFO] [stderr] 55 |         summed[i] += summed[i - 1].clone();
[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 rmcmc 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(associated_type_defaults)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rmcmc`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "3f7126af673c683bd0439f52b77a735069519fe8927df98efc4755b977cf7754"`
[INFO] running `"docker" "rm" "-f" "3f7126af673c683bd0439f52b77a735069519fe8927df98efc4755b977cf7754"`
[INFO] [stdout] 3f7126af673c683bd0439f52b77a735069519fe8927df98efc4755b977cf7754