[INFO] cloning repository https://github.com/kasbah/looper
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kasbah/looper" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkasbah%2Flooper", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkasbah%2Flooper'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a10931cef6ed86e1cec237eebe8645385f2a9d42
[INFO] testing kasbah/looper against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkasbah%2Flooper" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kasbah/looper on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/kasbah/looper
[INFO] finished tweaking git repo https://github.com/kasbah/looper
[INFO] tweaked toml for git repo https://github.com/kasbah/looper written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/kasbah/looper already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f4b5ecf89410fe0b75b93a216d4b8c19cfe6eb0300f218277804b64596232533
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "f4b5ecf89410fe0b75b93a216d4b8c19cfe6eb0300f218277804b64596232533", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f4b5ecf89410fe0b75b93a216d4b8c19cfe6eb0300f218277804b64596232533", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f4b5ecf89410fe0b75b93a216d4b8c19cfe6eb0300f218277804b64596232533", kill_on_drop: false }`
[INFO] [stdout] f4b5ecf89410fe0b75b93a216d4b8c19cfe6eb0300f218277804b64596232533
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3e9bdd20b5ef7daab433f1d4153fd0ec23c757ada5adb2cc1662cf7e5e6c113e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "3e9bdd20b5ef7daab433f1d4153fd0ec23c757ada5adb2cc1662cf7e5e6c113e", kill_on_drop: false }`
[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/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Read`
[INFO] [stdout]  --> src/main.rs:4:21
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::{self, Read};
[INFO] [stdout]   |                     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Playing`
[INFO] [stdout]  --> src/looper.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     Playing,
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Recording`
[INFO] [stdout]  --> src/looper.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Recording,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:75:17
[INFO] [stdout]    |
[INFO] [stdout] 75 |                 tx.send(Messages::SetThru(1.0));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:79:17
[INFO] [stdout]    |
[INFO] [stdout] 79 |                 tx.send(Messages::SetThru(0.0));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: linking with `cc` failed: exit code: 1
[INFO] [stdout]   |
[INFO] [stdout]   = note: "cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-m64" "-Wl,--eh-frame-hdr" "-L" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.0.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.1.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.10.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.11.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.12.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.13.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.14.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.15.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.2.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.3.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.4.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.5.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.6.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.7.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.8.rcgu.o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.looper.b2t4ctrl-cgu.9.rcgu.o" "-o" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb" "/opt/rustwide/target/debug/deps/looper-23f04496732fddeb.4llaoia9kxpc4n1v.rcgu.o" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/opt/rustwide/target/debug/deps" "-L" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/opt/rustwide/target/debug/deps/libjack-3f84c7312a0d3947.rlib" "/opt/rustwide/target/debug/deps/liblazy_static-6cd99bbe299abb0c.rlib" "/opt/rustwide/target/debug/deps/libjack_sys-51186d7ee7dbc9c1.rlib" "/opt/rustwide/target/debug/deps/liblibc-5f330032f7404cc7.rlib" "/opt/rustwide/target/debug/deps/libbitflags-2660c594cf04f3b5.rlib" "-Wl,--start-group" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-e12de7683a34c500.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-446a53c2e468675f.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libminiz_oxide-86fef9fb252a2d33.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler-3bed9bfd30304751.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libobject-0e38eeb474a7b386.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libaddr2line-a846ed547b824740.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libgimli-c9540f0a4fb9265d.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_demangle-7d2ca66c92c356eb.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libhashbrown-147e2c808f949493.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_alloc-bd2a4369506670e9.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-74bfdd0ce7d0ed48.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcfg_if-6777f47f1c491841.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-b104f1790174f2be.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-db37898996f45c13.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-25b7435131fc4938.rlib" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-9d4b6f3c097e876e.rlib" "-Wl,--end-group" "/opt/rustwide/rustup-home/toolchains/1.49.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-3f953ad652ab829a.rlib" "-Wl,-Bdynamic" "-ljack" "-lutil" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc"
[INFO] [stdout]   = note: /usr/bin/ld: cannot find -ljack
[INFO] [stdout]           collect2: error: ld returned 1 exit status
[INFO] [stdout]           
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `looper`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "3e9bdd20b5ef7daab433f1d4153fd0ec23c757ada5adb2cc1662cf7e5e6c113e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3e9bdd20b5ef7daab433f1d4153fd0ec23c757ada5adb2cc1662cf7e5e6c113e", kill_on_drop: false }`
[INFO] [stdout] 3e9bdd20b5ef7daab433f1d4153fd0ec23c757ada5adb2cc1662cf7e5e6c113e