[INFO] updating cached repository iovxw/babel
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/iovxw/babel
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/iovxw/babel" "work/ex/beta-1.38-1/sources/1.37.0/gh/iovxw/babel"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/iovxw/babel'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/iovxw/babel" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/iovxw/babel"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/iovxw/babel'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d01d16153443656cfc54338c07c738aca881a401
[INFO] sha for GitHub repo iovxw/babel: d01d16153443656cfc54338c07c738aca881a401
[INFO] validating manifest of iovxw/babel 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 iovxw/babel 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 iovxw/babel
[INFO] finished frobbing iovxw/babel
[INFO] frobbed toml for iovxw/babel written to work/ex/beta-1.38-1/sources/1.37.0/gh/iovxw/babel/Cargo.toml
[INFO] started frobbing iovxw/babel
[INFO] finished frobbing iovxw/babel
[INFO] frobbed toml for iovxw/babel written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/iovxw/babel/Cargo.toml
[INFO] crate iovxw/babel 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 iovxw/babel against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-7/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/iovxw/babel:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] e9bdd25ff0bb42cd6fd9b27c7e2a83a062f6e07940119b9f9ac291dd1e5c8116
[INFO] running `"docker" "start" "-a" "e9bdd25ff0bb42cd6fd9b27c7e2a83a062f6e07940119b9f9ac291dd1e5c8116"`
[INFO] [stderr]    Compiling utf-8 v0.7.4
[INFO] [stderr]    Compiling derive_builder v0.5.1
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.2
[INFO] [stderr]    Compiling termcolor v1.0.3
[INFO] [stderr]    Compiling ego-tree v0.5.0
[INFO] [stderr]    Compiling htmlescape v0.3.1
[INFO] [stderr]    Compiling arrayvec v0.4.7
[INFO] [stderr]    Compiling unicase v2.1.0
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/pin-utils-0.1.0-alpha.2/src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(pin)]
[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 `pin-utils`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "e9bdd25ff0bb42cd6fd9b27c7e2a83a062f6e07940119b9f9ac291dd1e5c8116"`
[INFO] running `"docker" "rm" "-f" "e9bdd25ff0bb42cd6fd9b27c7e2a83a062f6e07940119b9f9ac291dd1e5c8116"`
[INFO] [stdout] e9bdd25ff0bb42cd6fd9b27c7e2a83a062f6e07940119b9f9ac291dd1e5c8116