[INFO] updating cached repository CircuitCoder/stammer
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/CircuitCoder/stammer
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/CircuitCoder/stammer" "work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/stammer"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/stammer'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/CircuitCoder/stammer" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/CircuitCoder/stammer"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/CircuitCoder/stammer'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d3a1d5dc7ad3e2cc6aa56b6c2bf524a62bd488ed
[INFO] sha for GitHub repo CircuitCoder/stammer: d3a1d5dc7ad3e2cc6aa56b6c2bf524a62bd488ed
[INFO] validating manifest of CircuitCoder/stammer 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/stammer 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/stammer
[INFO] disabled cargo feature 'default-run' from CircuitCoder/stammer
[INFO] finished frobbing CircuitCoder/stammer
[INFO] frobbed toml for CircuitCoder/stammer written to work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/stammer/Cargo.toml
[INFO] started frobbing CircuitCoder/stammer
[INFO] disabled cargo feature 'default-run' from CircuitCoder/stammer
[INFO] finished frobbing CircuitCoder/stammer
[INFO] frobbed toml for CircuitCoder/stammer written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/CircuitCoder/stammer/Cargo.toml
[INFO] crate CircuitCoder/stammer 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/stammer 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-3/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/CircuitCoder/stammer:/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] 7636bd926086733e205a96727618ac44deb19652819cbbdc5c114cc91799a810
[INFO] running `"docker" "start" "-a" "7636bd926086733e205a96727618ac44deb19652819cbbdc5c114cc91799a810"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v0.15.31
[INFO] [stderr]    Compiling pinyin v0.5.0
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling backtrace v0.3.15
[INFO] [stderr]    Compiling phf_codegen v0.7.24
[INFO] [stderr]    Compiling jieba-rs v0.2.6
[INFO] [stderr]    Compiling serde_derive v1.0.90
[INFO] [stderr]    Compiling synstructure v0.10.1
[INFO] [stderr]    Compiling structopt-derive v0.2.15
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling structopt v0.2.15
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling serde v1.0.90
[INFO] [stderr]    Compiling hashbrown v0.2.1
[INFO] [stderr]    Compiling serde_json v1.0.39
[INFO] [stderr]    Compiling stammer v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/bin/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(custom_attribute)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/bin/tester.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(try_blocks)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `stammer`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/bin/trainer.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(try_blocks)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/bin/trainer.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(custom_attribute)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `serde::Deserialize`
[INFO] [stderr]  --> src/bin/trainer.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 | use serde::Deserialize;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `stammer`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[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 `stammer`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "7636bd926086733e205a96727618ac44deb19652819cbbdc5c114cc91799a810"`
[INFO] running `"docker" "rm" "-f" "7636bd926086733e205a96727618ac44deb19652819cbbdc5c114cc91799a810"`
[INFO] [stdout] 7636bd926086733e205a96727618ac44deb19652819cbbdc5c114cc91799a810