[INFO] cloning repository https://github.com/gyng/midi-to-wav
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gyng/midi-to-wav" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidi-to-wav", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidi-to-wav'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8a7e02bf9404ecc08e20efeb69d41aff5206029c
[INFO] testing gyng/midi-to-wav against 1.54.0 for beta-1.55-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidi-to-wav" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/gyng/midi-to-wav on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/gyng/midi-to-wav
[INFO] finished tweaking git repo https://github.com/gyng/midi-to-wav
[INFO] tweaked toml for git repo https://github.com/gyng/midi-to-wav written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/gyng/midi-to-wav already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 39eea56225704d8d161f6dded17e1b5d4d2332b5c9de459a0d153d940d533d4c
[INFO] running `Command { std: "docker" "start" "-a" "39eea56225704d8d161f6dded17e1b5d4d2332b5c9de459a0d153d940d533d4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "39eea56225704d8d161f6dded17e1b5d4d2332b5c9de459a0d153d940d533d4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39eea56225704d8d161f6dded17e1b5d4d2332b5c9de459a0d153d940d533d4c", kill_on_drop: false }`
[INFO] [stdout] 39eea56225704d8d161f6dded17e1b5d4d2332b5c9de459a0d153d940d533d4c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d3ebf9e2d7001fabc1d484272300d564451d3ed78b14b8cb03ca513dc56f5c8d
[INFO] running `Command { std: "docker" "start" "-a" "d3ebf9e2d7001fabc1d484272300d564451d3ed78b14b8cb03ca513dc56f5c8d", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling num-integer v0.1.39
[INFO] [stderr]    Compiling num-bigint v0.2.1
[INFO] [stderr]    Compiling num-complex v0.2.1
[INFO] [stderr]    Compiling num-rational v0.2.1
[INFO] [stderr]    Compiling num-iter v0.1.37
[INFO] [stderr]    Compiling ucd-util v0.1.2
[INFO] [stderr]    Compiling regex v1.0.5
[INFO] [stderr]    Compiling byteorder v1.2.7
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stderr]    Compiling rand_core v0.2.2
[INFO] [stderr]    Compiling quote v0.6.9
[INFO] [stderr]    Compiling syn v0.15.18
[INFO] [stderr]    Compiling rand v0.5.5
[INFO] [stderr]    Compiling regex-syntax v0.6.2
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling aho-corasick v0.6.9
[INFO] [stderr]    Compiling serde_derive v1.0.80
[INFO] [stderr]    Compiling num v0.2.0
[INFO] [stderr]    Compiling synthrs v0.1.0 (https://github.com/gyng/synthrs?rev=9e9724c2a970c1da15147c4ff603c7d24c258abc#9e9724c2)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/git/checkouts/synthrs-a4b8c03c849616c3/9e9724c/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(fn_traits, unboxed_closures)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `synthrs`
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "d3ebf9e2d7001fabc1d484272300d564451d3ed78b14b8cb03ca513dc56f5c8d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3ebf9e2d7001fabc1d484272300d564451d3ed78b14b8cb03ca513dc56f5c8d", kill_on_drop: false }`
[INFO] [stdout] d3ebf9e2d7001fabc1d484272300d564451d3ed78b14b8cb03ca513dc56f5c8d
