[INFO] updating cached repository derricw/rustrsa
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/derricw/rustrsa
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/derricw/rustrsa" "work/ex/beta-1.38-1/sources/1.37.0/gh/derricw/rustrsa"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/derricw/rustrsa'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/derricw/rustrsa" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/derricw/rustrsa"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/derricw/rustrsa'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 25a5a991e8504b1792617e5bff272b15539ea3af
[INFO] sha for GitHub repo derricw/rustrsa: 25a5a991e8504b1792617e5bff272b15539ea3af
[INFO] validating manifest of derricw/rustrsa 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 derricw/rustrsa 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 derricw/rustrsa
[INFO] finished frobbing derricw/rustrsa
[INFO] frobbed toml for derricw/rustrsa written to work/ex/beta-1.38-1/sources/1.37.0/gh/derricw/rustrsa/Cargo.toml
[INFO] started frobbing derricw/rustrsa
[INFO] finished frobbing derricw/rustrsa
[INFO] frobbed toml for derricw/rustrsa written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/derricw/rustrsa/Cargo.toml
[INFO] crate derricw/rustrsa 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]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing derricw/rustrsa 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/derricw/rustrsa:/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] 4dae14cfe077436ebad03c9cdc2228f037a50066f4672efa82b9bffe33f241eb
[INFO] running `"docker" "start" "-a" "4dae14cfe077436ebad03c9cdc2228f037a50066f4672efa82b9bffe33f241eb"`
[INFO] [stderr]    Compiling num-complex v0.2.0
[INFO] [stderr]    Compiling num-iter v0.1.37
[INFO] [stderr]    Compiling rustc-cfg v0.2.0
[INFO] [stderr]    Compiling hamming v0.1.3
[INFO] [stderr]    Compiling ieee754 v0.2.2
[INFO] [stderr]    Compiling num-rational v0.2.1
[INFO] [stderr]    Compiling ramp v0.5.0
[INFO] [stderr]    Compiling num v0.2.0
[INFO] [stderr]    Compiling mod_exp v1.0.0
[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-0.5.0/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-0.5.0/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] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "4dae14cfe077436ebad03c9cdc2228f037a50066f4672efa82b9bffe33f241eb"`
[INFO] running `"docker" "rm" "-f" "4dae14cfe077436ebad03c9cdc2228f037a50066f4672efa82b9bffe33f241eb"`
[INFO] [stdout] 4dae14cfe077436ebad03c9cdc2228f037a50066f4672efa82b9bffe33f241eb