[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] checking gyng/midi-to-wav against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidi-to-wav" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/gyng/midi-to-wav on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", 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-8/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" "+beta" "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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1136fe37cb6b82a97532b74b63b0a65021557b827698676feb768df0fe7304df
[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" "1136fe37cb6b82a97532b74b63b0a65021557b827698676feb768df0fe7304df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1136fe37cb6b82a97532b74b63b0a65021557b827698676feb768df0fe7304df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1136fe37cb6b82a97532b74b63b0a65021557b827698676feb768df0fe7304df", kill_on_drop: false }`
[INFO] [stdout] 1136fe37cb6b82a97532b74b63b0a65021557b827698676feb768df0fe7304df
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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=forbid" "-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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d7ec8399a1e38d08b78d387cda84f1792118479c4754a019eb9b4c81b008374f
[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" "d7ec8399a1e38d08b78d387cda84f1792118479c4754a019eb9b4c81b008374f", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling num-bigint v0.2.1
[INFO] [stderr]    Compiling syn v0.15.18
[INFO] [stderr]     Checking num-integer v0.1.39
[INFO] [stderr]     Checking num-complex v0.2.1
[INFO] [stderr]     Checking num-iter v0.1.37
[INFO] [stderr]    Compiling serde_derive v1.0.80
[INFO] [stderr]     Checking num-rational v0.2.1
[INFO] [stderr]     Checking num v0.2.0
[INFO] [stderr]     Checking synthrs v0.1.0 (https://github.com/gyng/synthrs?rev=9e9724c2a970c1da15147c4ff603c7d24c258abc#9e9724c2)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta 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] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `synthrs`
[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" "d7ec8399a1e38d08b78d387cda84f1792118479c4754a019eb9b4c81b008374f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d7ec8399a1e38d08b78d387cda84f1792118479c4754a019eb9b4c81b008374f", kill_on_drop: false }`
[INFO] [stdout] d7ec8399a1e38d08b78d387cda84f1792118479c4754a019eb9b4c81b008374f