[INFO] crate loop-forever 1.0.2 is already in cache
[INFO] extracting crate loop-forever 1.0.2 into work/ex/beta-1.38-1/sources/1.37.0/reg/loop-forever/1.0.2
[INFO] extracting crate loop-forever 1.0.2 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/loop-forever/1.0.2
[INFO] validating manifest of loop-forever-1.0.2 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 loop-forever-1.0.2 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 loop-forever-1.0.2
[INFO] finished frobbing loop-forever-1.0.2
[INFO] frobbed toml for loop-forever-1.0.2 written to work/ex/beta-1.38-1/sources/1.37.0/reg/loop-forever/1.0.2/Cargo.toml
[INFO] started frobbing loop-forever-1.0.2
[INFO] finished frobbing loop-forever-1.0.2
[INFO] frobbed toml for loop-forever-1.0.2 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/loop-forever/1.0.2/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 loop-forever-1.0.2 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-3/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/loop-forever/1.0.2:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 3a0aa8458d8dbb87f8fcdb99685ead770cf0d27d871a455b6549ed658d8c12a0
[INFO] running `"docker" "start" "-a" "3a0aa8458d8dbb87f8fcdb99685ead770cf0d27d871a455b6549ed658d8c12a0"`
[INFO] [stderr]    Compiling loop-forever v1.0.2 (/opt/crater/workdir)
[INFO] [stderr] error[E0464]: multiple matching crates for `libc`
[INFO] [stderr]  --> src/forever.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | extern crate libc;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: candidates:
[INFO] [stderr]           crate `libc`: /opt/crater/rustup-home/toolchains/beta-2019-08-13-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-bba1c7ef9e950882.rlib
[INFO] [stderr]           crate `libc`: /opt/crater/rustup-home/toolchains/beta-2019-08-13-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-4605024e2da1b6db.rlib
[INFO] [stderr] 
[INFO] [stderr] error[E0463]: can't find crate for `libc`
[INFO] [stderr]  --> src/forever.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | 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 `loop-forever`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "3a0aa8458d8dbb87f8fcdb99685ead770cf0d27d871a455b6549ed658d8c12a0"`
[INFO] running `"docker" "rm" "-f" "3a0aa8458d8dbb87f8fcdb99685ead770cf0d27d871a455b6549ed658d8c12a0"`
[INFO] [stdout] 3a0aa8458d8dbb87f8fcdb99685ead770cf0d27d871a455b6549ed658d8c12a0