[INFO] crate rustcov 0.0.0 is already in cache
[INFO] extracting crate rustcov 0.0.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/rustcov/0.0.0
[INFO] extracting crate rustcov 0.0.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustcov/0.0.0
[INFO] validating manifest of rustcov-0.0.0 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 rustcov-0.0.0 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 rustcov-0.0.0
[INFO] finished frobbing rustcov-0.0.0
[INFO] frobbed toml for rustcov-0.0.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/rustcov/0.0.0/Cargo.toml
[INFO] started frobbing rustcov-0.0.0
[INFO] finished frobbing rustcov-0.0.0
[INFO] frobbed toml for rustcov-0.0.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustcov/0.0.0/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] testing rustcov-0.0.0 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-0/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustcov/0.0.0:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] d94b70c0c2a62b71006d6315dc8a7e9f0268d1f491d33d2f7fc7291809306d0f
[INFO] running `"docker" "start" "-a" "d94b70c0c2a62b71006d6315dc8a7e9f0268d1f491d33d2f7fc7291809306d0f"`
[INFO] [stderr]    Compiling rustcov v0.0.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.21s
[INFO] running `"docker" "inspect" "d94b70c0c2a62b71006d6315dc8a7e9f0268d1f491d33d2f7fc7291809306d0f"`
[INFO] running `"docker" "rm" "-f" "d94b70c0c2a62b71006d6315dc8a7e9f0268d1f491d33d2f7fc7291809306d0f"`
[INFO] [stdout] d94b70c0c2a62b71006d6315dc8a7e9f0268d1f491d33d2f7fc7291809306d0f
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustcov/0.0.0:/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" "+beta-2019-08-13" "test" "--frozen" "--no-run"`
[INFO] [stdout] ac84545ec157d6536f8b26eccb88d25ac1f8a07181cd7ce4c9e93ff32f4959f5
[INFO] running `"docker" "start" "-a" "ac84545ec157d6536f8b26eccb88d25ac1f8a07181cd7ce4c9e93ff32f4959f5"`
[INFO] [stderr]    Compiling rustcov v0.0.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0457]: plugin `rustcov` only found in rlib format, but must be available in dylib format
[INFO] [stderr]  --> examples/plugin.rs:2:11
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![plugin(rustcov)]
[INFO] [stderr]   |           ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> examples/plugin.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(plugin)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `plugin`
[INFO] [stderr]   |
[INFO] [stderr]   = note: consider adding a `main` function to `examples/plugin.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0601.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rustcov`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "ac84545ec157d6536f8b26eccb88d25ac1f8a07181cd7ce4c9e93ff32f4959f5"`
[INFO] running `"docker" "rm" "-f" "ac84545ec157d6536f8b26eccb88d25ac1f8a07181cd7ce4c9e93ff32f4959f5"`
[INFO] [stdout] ac84545ec157d6536f8b26eccb88d25ac1f8a07181cd7ce4c9e93ff32f4959f5