[INFO] crate rustbar 0.2.0 is already in cache
[INFO] extracting crate rustbar 0.2.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/rustbar/0.2.0
[INFO] extracting crate rustbar 0.2.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustbar/0.2.0
[INFO] validating manifest of rustbar-0.2.0 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 rustbar-0.2.0 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 rustbar-0.2.0
[INFO] finished frobbing rustbar-0.2.0
[INFO] frobbed toml for rustbar-0.2.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/rustbar/0.2.0/Cargo.toml
[INFO] started frobbing rustbar-0.2.0
[INFO] finished frobbing rustbar-0.2.0
[INFO] frobbed toml for rustbar-0.2.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustbar/0.2.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing rustbar-0.2.0 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-7/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/rustbar/0.2.0:/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] 59abd5ec7bbcc9810981d2ab18c1ec579d250ed32f8dcd9ed76004cfbe1c281c
[INFO] running `"docker" "start" "-a" "59abd5ec7bbcc9810981d2ab18c1ec579d250ed32f8dcd9ed76004cfbe1c281c"`
[INFO] [stderr]    Compiling rustbar v0.2.0 (/opt/crater/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" "59abd5ec7bbcc9810981d2ab18c1ec579d250ed32f8dcd9ed76004cfbe1c281c"`
[INFO] running `"docker" "rm" "-f" "59abd5ec7bbcc9810981d2ab18c1ec579d250ed32f8dcd9ed76004cfbe1c281c"`
[INFO] [stdout] 59abd5ec7bbcc9810981d2ab18c1ec579d250ed32f8dcd9ed76004cfbe1c281c