[INFO] updating cached repository https://github.com/drone-os/itmsink
[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] 953ca7ed7d190a3c93d6663306bc01388474afba
[INFO] testing drone-os/itmsink against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdrone-os%2Fitmsink" "work/builds/worker-2/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/drone-os/itmsink 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/drone-os/itmsink
[INFO] finished tweaking git repo https://github.com/drone-os/itmsink
[INFO] tweaked toml for git repo https://github.com/drone-os/itmsink written to work/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/drone-os/itmsink 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-2/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-2/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] e7015fd07422260575eef4276a6c66332822ca7024b92eedabacb8be0fe546b7
[INFO] running `"docker" "start" "-a" "e7015fd07422260575eef4276a6c66332822ca7024b92eedabacb8be0fe546b7"`
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling structopt-derive v0.3.2
[INFO] [stderr]    Compiling env_logger v0.6.2
[INFO] [stderr]    Compiling backtrace v0.3.37
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling exitfailure v0.5.1
[INFO] [stderr]    Compiling structopt v0.3.2
[INFO] [stderr]    Compiling itmsink v0.1.2 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:24:1
[INFO] [stderr]    |
[INFO] [stderr] 24 | #![feature(exhaustive_patterns)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:25:1
[INFO] [stderr]    |
[INFO] [stderr] 25 | #![feature(generator_trait)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:26:1
[INFO] [stderr]    |
[INFO] [stderr] 26 | #![feature(generators)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:27:1
[INFO] [stderr]    |
[INFO] [stderr] 27 | #![feature(never_type)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `itmsink`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "e7015fd07422260575eef4276a6c66332822ca7024b92eedabacb8be0fe546b7"`
[INFO] running `"docker" "rm" "-f" "e7015fd07422260575eef4276a6c66332822ca7024b92eedabacb8be0fe546b7"`
[INFO] [stdout] e7015fd07422260575eef4276a6c66332822ca7024b92eedabacb8be0fe546b7