[INFO] updating cached repository https://github.com/ggomagundan/restful_example
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 94c9e3291cf852908a877b5312fb248fd6ac212b
[INFO] testing ggomagundan/restful_example against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fggomagundan%2Frestful_example" "work/builds/worker-1/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ggomagundan/restful_example on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/ggomagundan/restful_example
[INFO] finished tweaking git repo https://github.com/ggomagundan/restful_example
[INFO] tweaked toml for git repo https://github.com/ggomagundan/restful_example written to work/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/ggomagundan/restful_example already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-1/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] aa936966132f3cc8df75b167a6dda635a667aebc28cbd722ec603b50417dd395
[INFO] running `"docker" "start" "-a" "aa936966132f3cc8df75b167a6dda635a667aebc28cbd722ec603b50417dd395"`
[INFO] [stderr]    Compiling either v1.5.2
[INFO] [stderr]    Compiling memchr v0.1.11
[INFO] [stderr]    Compiling buf_redux v0.8.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling thread-id v2.0.0
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling cookie v0.11.0
[INFO] [stderr]    Compiling proc-macro-hack v0.5.5
[INFO] [stderr]    Compiling serde_qs v0.4.5
[INFO] [stderr]    Compiling dotenv v0.13.0
[INFO] [stderr]    Compiling thread_local v0.2.7
[INFO] [stderr]    Compiling aho-corasick v0.5.3
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.14
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/futures-core-preview-0.3.0-alpha.14/src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(futures_api)]
[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 `futures-core-preview`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "aa936966132f3cc8df75b167a6dda635a667aebc28cbd722ec603b50417dd395"`
[INFO] running `"docker" "rm" "-f" "aa936966132f3cc8df75b167a6dda635a667aebc28cbd722ec603b50417dd395"`
[INFO] [stdout] aa936966132f3cc8df75b167a6dda635a667aebc28cbd722ec603b50417dd395