[INFO] crate mach 0.3.2 is already in cache
[INFO] extracting crate mach 0.3.2 into work/ex/beta-1.38-1/sources/1.37.0/reg/mach/0.3.2
[INFO] extracting crate mach 0.3.2 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/mach/0.3.2
[INFO] validating manifest of mach-0.3.2 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 mach-0.3.2 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 mach-0.3.2
[INFO] finished frobbing mach-0.3.2
[INFO] frobbed toml for mach-0.3.2 written to work/ex/beta-1.38-1/sources/1.37.0/reg/mach/0.3.2/Cargo.toml
[INFO] started frobbing mach-0.3.2
[INFO] finished frobbing mach-0.3.2
[INFO] frobbed toml for mach-0.3.2 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/mach/0.3.2/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 mach-0.3.2 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/mach/0.3.2:/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] 1b19fdedf76346496f9812d0b4414826dbc3ed7e20b0e2ea3ad2d18bd652ea68
[INFO] running `"docker" "start" "-a" "1b19fdedf76346496f9812d0b4414826dbc3ed7e20b0e2ea3ad2d18bd652ea68"`
[INFO] [stderr]    Compiling mach v0.3.2 (/opt/crater/workdir)
[INFO] [stderr] error[E0464]: multiple matching crates for `libc`
[INFO] [stderr]   --> src/lib.rs:21:1
[INFO] [stderr]    |
[INFO] [stderr] 21 | extern crate libc;
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: candidates:
[INFO] [stderr]            crate `libc`: /opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-2299a069d4067a08.rlib
[INFO] [stderr]            crate `libc`: /opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-d6459c4f0817c67c.rlib
[INFO] [stderr] 
[INFO] [stderr] error[E0463]: can't find crate for `libc`
[INFO] [stderr]   --> src/lib.rs:21:1
[INFO] [stderr]    |
[INFO] [stderr] 21 | extern crate libc;
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^ can't find crate
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error: Could not compile `mach`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "1b19fdedf76346496f9812d0b4414826dbc3ed7e20b0e2ea3ad2d18bd652ea68"`
[INFO] running `"docker" "rm" "-f" "1b19fdedf76346496f9812d0b4414826dbc3ed7e20b0e2ea3ad2d18bd652ea68"`
[INFO] [stdout] 1b19fdedf76346496f9812d0b4414826dbc3ed7e20b0e2ea3ad2d18bd652ea68