[INFO] updating cached repository CircuitCoder/slowrsa
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/CircuitCoder/slowrsa
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/CircuitCoder/slowrsa" "work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/slowrsa"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/slowrsa'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/CircuitCoder/slowrsa" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/CircuitCoder/slowrsa"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/CircuitCoder/slowrsa'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9f0258a66b9df99771704767551e9e8506997c11
[INFO] sha for GitHub repo CircuitCoder/slowrsa: 9f0258a66b9df99771704767551e9e8506997c11
[INFO] validating manifest of CircuitCoder/slowrsa 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 CircuitCoder/slowrsa 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 CircuitCoder/slowrsa
[INFO] finished frobbing CircuitCoder/slowrsa
[INFO] frobbed toml for CircuitCoder/slowrsa written to work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/slowrsa/Cargo.toml
[INFO] started frobbing CircuitCoder/slowrsa
[INFO] finished frobbing CircuitCoder/slowrsa
[INFO] frobbed toml for CircuitCoder/slowrsa written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/CircuitCoder/slowrsa/Cargo.toml
[INFO] crate CircuitCoder/slowrsa 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 CircuitCoder/slowrsa 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/slowrsa:/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] 0021514a0a06cc6d34702c6557840c07f38b6937640761ea33294be34989fa2f
[INFO] running `"docker" "start" "-a" "0021514a0a06cc6d34702c6557840c07f38b6937640761ea33294be34989fa2f"`
[INFO] [stderr]    Compiling syn v0.15.38
[INFO] [stderr]    Compiling rustc-cfg v0.2.0
[INFO] [stderr]    Compiling num-bigint v0.2.2
[INFO] [stderr]    Compiling paw-raw v1.0.0
[INFO] [stderr]    Compiling ieee754 v0.2.6
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling num-bigint v0.1.44
[INFO] [stderr]    Compiling ramp v0.5.1
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/ramp-0.5.1/src/lib.rs:18:1
[INFO] [stderr]    |
[INFO] [stderr] 18 | #![feature(core_intrinsics, asm, allocator_api)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/ramp-0.5.1/src/lib.rs:19:1
[INFO] [stderr]    |
[INFO] [stderr] 19 | #![feature(step_trait, ptr_internals, alloc, raw_vec_internals)]
[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 `ramp`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "0021514a0a06cc6d34702c6557840c07f38b6937640761ea33294be34989fa2f"`
[INFO] running `"docker" "rm" "-f" "0021514a0a06cc6d34702c6557840c07f38b6937640761ea33294be34989fa2f"`
[INFO] [stdout] 0021514a0a06cc6d34702c6557840c07f38b6937640761ea33294be34989fa2f