[INFO] updating cached repository kasbah/looper
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/kasbah/looper
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/kasbah/looper" "work/ex/beta-1.38-1/sources/1.37.0/gh/kasbah/looper"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/kasbah/looper'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/kasbah/looper" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/kasbah/looper"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/kasbah/looper'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a10931cef6ed86e1cec237eebe8645385f2a9d42
[INFO] sha for GitHub repo kasbah/looper: a10931cef6ed86e1cec237eebe8645385f2a9d42
[INFO] validating manifest of kasbah/looper 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 kasbah/looper 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 kasbah/looper
[INFO] finished frobbing kasbah/looper
[INFO] frobbed toml for kasbah/looper written to work/ex/beta-1.38-1/sources/1.37.0/gh/kasbah/looper/Cargo.toml
[INFO] started frobbing kasbah/looper
[INFO] finished frobbing kasbah/looper
[INFO] frobbed toml for kasbah/looper written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/kasbah/looper/Cargo.toml
[INFO] crate kasbah/looper already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing kasbah/looper 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-2/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/kasbah/looper:/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] 5f60fc8b733c116cc876db9487b0bb92ba8da26b20b366fd4d4e30d41ce9017a
[INFO] running `"docker" "start" "-a" "5f60fc8b733c116cc876db9487b0bb92ba8da26b20b366fd4d4e30d41ce9017a"`
[INFO] [stderr]    Compiling jack-sys v0.1.4
[INFO] [stderr]    Compiling jack v0.5.0 (https://github.com/RustAudio/rust-jack.git#c352502e)
[INFO] [stderr]    Compiling looper v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `Read`
[INFO] [stderr]  --> src/main.rs:4:21
[INFO] [stderr]   |
[INFO] [stderr] 4 | use std::io::{self, Read};
[INFO] [stderr]   |                     ^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Playing`
[INFO] [stderr]  --> src/looper.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     Playing,
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Recording`
[INFO] [stderr]  --> src/looper.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 |     Recording,
[INFO] [stderr]   |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:75:17
[INFO] [stderr]    |
[INFO] [stderr] 75 |                 tx.send(Messages::SetThru(1.0));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:79:17
[INFO] [stderr]    |
[INFO] [stderr] 79 |                 tx.send(Messages::SetThru(0.0));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] error: linking with `cc` failed: exit code: 1
[INFO] [stderr]   |
[INFO] [stderr]   = note: "cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-m64" "-L" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.0.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.1.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.10.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.11.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.12.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.13.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.14.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.15.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.2.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.3.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.4.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.5.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.6.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.7.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.8.rcgu.o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.looper.bzufzj89-cgu.9.rcgu.o" "-o" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8" "/opt/crater/target/debug/deps/looper-e6cdaacf6b10aee8.423yqnvn76myuzv.rcgu.o" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/opt/crater/target/debug/deps" "-L" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/opt/crater/target/debug/deps/libjack-627ac8c12076e2e0.rlib" "/opt/crater/target/debug/deps/liblazy_static-ccea4a44c4af410d.rlib" "/opt/crater/target/debug/deps/libjack_sys-6e4a87627353cc9c.rlib" "/opt/crater/target/debug/deps/liblibc-52f8c12df0d13af1.rlib" "/opt/crater/target/debug/deps/libbitflags-05fa20c47058c1db.rlib" "-Wl,--start-group" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-4a76ff35a356aedf.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-e11c7b3b3225afe2.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libbacktrace-13217ede3d276f16.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libbacktrace_sys-621a9ee22da6caa1.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_demangle-546c844e8071bbeb.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libhashbrown-be9569e4d599746f.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_alloc-47d8845cef2a3bc5.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-017511bce73a530c.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcfg_if-be7979c57a08057b.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-d6459c4f0817c67c.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-580035dd98451925.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-aee5c24fff305dea.rlib" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-8a55a4098920125a.rlib" "-Wl,--end-group" "/opt/crater/rustup-home/toolchains/1.37.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-9fc4b5be2ba5cc19.rlib" "-Wl,-Bdynamic" "-ljack" "-lutil" "-ldl" "-lrt" "-lpthread" "-lgcc_s" "-lc" "-lm" "-lrt" "-lpthread" "-lutil" "-lutil"
[INFO] [stderr]   = note: /usr/bin/ld: cannot find -ljack
[INFO] [stderr]           collect2: error: ld returned 1 exit status
[INFO] [stderr]           
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `looper`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "5f60fc8b733c116cc876db9487b0bb92ba8da26b20b366fd4d4e30d41ce9017a"`
[INFO] running `"docker" "rm" "-f" "5f60fc8b733c116cc876db9487b0bb92ba8da26b20b366fd4d4e30d41ce9017a"`
[INFO] [stdout] 5f60fc8b733c116cc876db9487b0bb92ba8da26b20b366fd4d4e30d41ce9017a