[INFO] crate libmount-sys 0.1.0 is already in cache
[INFO] extracting crate libmount-sys 0.1.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/libmount-sys/0.1.0
[INFO] extracting crate libmount-sys 0.1.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/libmount-sys/0.1.0
[INFO] validating manifest of libmount-sys-0.1.0 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 libmount-sys-0.1.0 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 libmount-sys-0.1.0
[INFO] finished frobbing libmount-sys-0.1.0
[INFO] frobbed toml for libmount-sys-0.1.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/libmount-sys/0.1.0/Cargo.toml
[INFO] started frobbing libmount-sys-0.1.0
[INFO] finished frobbing libmount-sys-0.1.0
[INFO] frobbed toml for libmount-sys-0.1.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/libmount-sys/0.1.0/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 libmount-sys-0.1.0 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-4/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/libmount-sys/0.1.0:/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] 801674820d7b48e5762fe3696f8c8b01544e510ff30de829472a5511bd93a754
[INFO] running `"docker" "start" "-a" "801674820d7b48e5762fe3696f8c8b01544e510ff30de829472a5511bd93a754"`
[INFO] [stderr]    Compiling libmount-sys v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::io::Write`
[INFO] [stderr]  --> build.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::io::Write;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `cdir`
[INFO] [stderr]  --> build.rs:7:7
[INFO] [stderr]   |
[INFO] [stderr] 7 |   let cdir = std::env::current_dir().unwrap();
[INFO] [stderr]   |       ^^^^ help: consider prefixing with an underscore: `_cdir`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] error: failed to run custom build command for `libmount-sys v0.1.0 (/opt/crater/workdir)`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/crater/target/debug/build/libmount-sys-070b8f35f75758e3/build-script-build` (exit code: 1)
[INFO] [stderr] --- stderr
[INFO] [stderr] pkg_config mount failed: `"pkg-config" "--libs" "--cflags" "mount"` did not exit successfully: exit code: 1
[INFO] [stderr] --- stderr
[INFO] [stderr] Package mount was not found in the pkg-config search path.
[INFO] [stderr] Perhaps you should add the directory containing `mount.pc'
[INFO] [stderr] to the PKG_CONFIG_PATH environment variable
[INFO] [stderr] No package 'mount' found
[INFO] [stderr] 
[INFO] [stderr] 
[INFO] running `"docker" "inspect" "801674820d7b48e5762fe3696f8c8b01544e510ff30de829472a5511bd93a754"`
[INFO] running `"docker" "rm" "-f" "801674820d7b48e5762fe3696f8c8b01544e510ff30de829472a5511bd93a754"`
[INFO] [stdout] 801674820d7b48e5762fe3696f8c8b01544e510ff30de829472a5511bd93a754