[INFO] crate rustbar 0.2.0 is already in cache
[INFO] testing rustbar-0.2.0 against 1.38.0 for beta-1.39-1
[INFO] extracting crate rustbar 0.2.0 into work/builds/worker-2/source
[INFO] validating manifest of crates.io crate rustbar 0.2.0 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 crates.io crate rustbar 0.2.0
[INFO] finished tweaking crates.io crate rustbar 0.2.0
[INFO] tweaked toml for crates.io crate rustbar 0.2.0 written to work/builds/worker-2/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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] 0568385bdbf987f3a8e3a81254bc5cdec6869112f2830441b0c5168eae22ec20
[INFO] running `"docker" "start" "-a" "0568385bdbf987f3a8e3a81254bc5cdec6869112f2830441b0c5168eae22ec20"`
[INFO] [stderr]    Compiling rustbar v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(libc)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: patterns aren't allowed in methods without bodies
[INFO] [stderr]   --> src/rustbars.rs:22:18
[INFO] [stderr]    |
[INFO] [stderr] 22 |     fn to_stderr(mut self) -> T;
[INFO] [stderr]    |                  ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(patterns_in_fns_without_body)]` on by default
[INFO] [stderr]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stderr]    = note: for more information, see issue #35203 <https://github.com/rust-lang/rust/issues/35203>
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'rustc_private': this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via `Cargo.toml` instead?
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | extern crate libc;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: for more information, see https://github.com/rust-lang/rust/issues/27812
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0658.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rustbar`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0568385bdbf987f3a8e3a81254bc5cdec6869112f2830441b0c5168eae22ec20"`
[INFO] running `"docker" "rm" "-f" "0568385bdbf987f3a8e3a81254bc5cdec6869112f2830441b0c5168eae22ec20"`
[INFO] [stdout] 0568385bdbf987f3a8e3a81254bc5cdec6869112f2830441b0c5168eae22ec20