[INFO] updating cached repository Arkweid/stellar-explorer-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Arkweid/stellar-explorer-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Arkweid/stellar-explorer-rust" "work/ex/beta-1.38-1/sources/1.37.0/gh/Arkweid/stellar-explorer-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Arkweid/stellar-explorer-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Arkweid/stellar-explorer-rust" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Arkweid/stellar-explorer-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Arkweid/stellar-explorer-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 22a608e07ae69192bd2329d220f107fcf116f1a8
[INFO] sha for GitHub repo Arkweid/stellar-explorer-rust: 22a608e07ae69192bd2329d220f107fcf116f1a8
[INFO] validating manifest of Arkweid/stellar-explorer-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 Arkweid/stellar-explorer-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 Arkweid/stellar-explorer-rust
[INFO] finished frobbing Arkweid/stellar-explorer-rust
[INFO] frobbed toml for Arkweid/stellar-explorer-rust written to work/ex/beta-1.38-1/sources/1.37.0/gh/Arkweid/stellar-explorer-rust/Cargo.toml
[INFO] started frobbing Arkweid/stellar-explorer-rust
[INFO] finished frobbing Arkweid/stellar-explorer-rust
[INFO] frobbed toml for Arkweid/stellar-explorer-rust written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Arkweid/stellar-explorer-rust/Cargo.toml
[INFO] crate Arkweid/stellar-explorer-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] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing Arkweid/stellar-explorer-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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/Arkweid/stellar-explorer-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] 653746bb106c6f7cc1631c584b4a43b62404092d74e5a6452c08e639ad0ea877
[INFO] running `"docker" "start" "-a" "653746bb106c6f7cc1631c584b4a43b62404092d74e5a6452c08e639ad0ea877"`
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.15
[INFO] [stderr]    Compiling handlebox v0.3.0
[INFO] [stderr]    Compiling crc16 v0.3.4
[INFO] [stderr]    Compiling runtime-fmt v0.3.0
[INFO] [stderr]    Compiling base32 v0.3.1
[INFO] [stderr]    Compiling ring v0.14.6
[INFO] [stderr]    Compiling debugit v0.1.2
[INFO] [stderr]    Compiling filetime v0.2.4
[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/runtime-fmt-0.3.0/src/lib.rs:17:1
[INFO] [stderr]    |
[INFO] [stderr] 17 | #![feature(fmt_internals)]
[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/runtime-fmt-0.3.0/src/lib.rs:18:1
[INFO] [stderr]    |
[INFO] [stderr] 18 | #![feature(conservative_impl_trait)]
[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/runtime-fmt-0.3.0/src/lib.rs:19:1
[INFO] [stderr]    |
[INFO] [stderr] 19 | #![feature(specialization)]
[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/runtime-fmt-0.3.0/src/lib.rs:20:1
[INFO] [stderr]    |
[INFO] [stderr] 20 | #![feature(print_internals)]
[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/runtime-fmt-0.3.0/src/lib.rs:21:1
[INFO] [stderr]    |
[INFO] [stderr] 21 | #![feature(rustc_private)]
[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/runtime-fmt-0.3.0/src/lib.rs:22:1
[INFO] [stderr]    |
[INFO] [stderr] 22 | #![feature(try_from)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]    Compiling xattr v0.2.2
[INFO] [stderr] error: aborting due to 6 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `runtime-fmt`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "653746bb106c6f7cc1631c584b4a43b62404092d74e5a6452c08e639ad0ea877"`
[INFO] running `"docker" "rm" "-f" "653746bb106c6f7cc1631c584b4a43b62404092d74e5a6452c08e639ad0ea877"`
[INFO] [stdout] 653746bb106c6f7cc1631c584b4a43b62404092d74e5a6452c08e639ad0ea877