[INFO] updating cached repository bhjoellund/fibver
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/bhjoellund/fibver
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/bhjoellund/fibver" "work/ex/beta-1.38-1/sources/1.37.0/gh/bhjoellund/fibver"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/bhjoellund/fibver'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/bhjoellund/fibver" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bhjoellund/fibver"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bhjoellund/fibver'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e3927920dae762cd8c93a574d8901e5133efcf6a
[INFO] sha for GitHub repo bhjoellund/fibver: e3927920dae762cd8c93a574d8901e5133efcf6a
[INFO] validating manifest of bhjoellund/fibver 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 bhjoellund/fibver 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 bhjoellund/fibver
[INFO] finished frobbing bhjoellund/fibver
[INFO] frobbed toml for bhjoellund/fibver written to work/ex/beta-1.38-1/sources/1.37.0/gh/bhjoellund/fibver/Cargo.toml
[INFO] started frobbing bhjoellund/fibver
[INFO] finished frobbing bhjoellund/fibver
[INFO] frobbed toml for bhjoellund/fibver written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/bhjoellund/fibver/Cargo.toml
[INFO] crate bhjoellund/fibver 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 bhjoellund/fibver 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-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/bhjoellund/fibver:/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] 5d6c856ba88a641a81dc99ed4ebb300af40b41187cea76829594c6665f179cb1
[INFO] running `"docker" "start" "-a" "5d6c856ba88a641a81dc99ed4ebb300af40b41187cea76829594c6665f179cb1"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling fibver v1.1.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(try_trait)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(int_error_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 `fibver`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "5d6c856ba88a641a81dc99ed4ebb300af40b41187cea76829594c6665f179cb1"`
[INFO] running `"docker" "rm" "-f" "5d6c856ba88a641a81dc99ed4ebb300af40b41187cea76829594c6665f179cb1"`
[INFO] [stdout] 5d6c856ba88a641a81dc99ed4ebb300af40b41187cea76829594c6665f179cb1