[INFO] cloning repository https://github.com/gyng/midcat
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gyng/midcat" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidcat", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidcat'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 77677cdabbb18277e6046fc1450d49895c30c61e
[INFO] testing gyng/midcat against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgyng%2Fmidcat" "/workspace/builds/worker-15/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-15/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/gyng/midcat on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/gyng/midcat
[INFO] finished tweaking git repo https://github.com/gyng/midcat
[INFO] tweaked toml for git repo https://github.com/gyng/midcat written to /workspace/builds/worker-15/source/Cargo.toml
[INFO] crate git repo https://github.com/gyng/midcat already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 509c4237f4aaecbb777ebc5bd87657d13bf45455785529b22ac230de06a88260
[INFO] running `Command { std: "docker" "start" "-a" "509c4237f4aaecbb777ebc5bd87657d13bf45455785529b22ac230de06a88260", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "509c4237f4aaecbb777ebc5bd87657d13bf45455785529b22ac230de06a88260", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "509c4237f4aaecbb777ebc5bd87657d13bf45455785529b22ac230de06a88260", kill_on_drop: false }`
[INFO] [stdout] 509c4237f4aaecbb777ebc5bd87657d13bf45455785529b22ac230de06a88260
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d23bf9caea4b4ebc4fded13bc774231f0147e290180a2a0b44698257790bcb53
[INFO] running `Command { std: "docker" "start" "-a" "d23bf9caea4b4ebc4fded13bc774231f0147e290180a2a0b44698257790bcb53", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling libc v0.2.32
[INFO] [stderr]    Compiling unicode-xid v0.0.4
[INFO] [stderr]    Compiling num-bigint v0.2.1
[INFO] [stderr]    Compiling quote v0.3.15
[INFO] [stderr]    Compiling pkg-config v0.3.9
[INFO] [stderr]    Compiling num-iter v0.1.37
[INFO] [stderr]    Compiling num-rational v0.2.1
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling num-complex v0.2.1
[INFO] [stderr]    Compiling lazy_static v0.2.9
[INFO] [stderr]    Compiling rand_core v0.3.0
[INFO] [stderr]    Compiling regex-syntax v0.4.1
[INFO] [stderr]    Compiling utf8-ranges v1.0.0
[INFO] [stderr]    Compiling strsim v0.6.0
[INFO] [stderr]    Compiling serde v1.0.15
[INFO] [stderr]    Compiling futures v0.1.16
[INFO] [stderr]    Compiling byteorder v1.2.7
[INFO] [stderr]    Compiling synom v0.11.3
[INFO] [stderr]    Compiling unreachable v1.0.0
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling alsa-sys v0.1.1
[INFO] [stderr]    Compiling thread_local v0.3.4
[INFO] [stderr]    Compiling rand_core v0.2.2
[INFO] [stderr]    Compiling memchr v1.0.1
[INFO] [stderr]    Compiling rand v0.5.5
[INFO] [stderr]    Compiling aho-corasick v0.6.3
[INFO] [stderr]    Compiling serde_derive_internals v0.16.0
[INFO] [stderr]    Compiling regex v0.2.2
[INFO] [stderr]    Compiling num-integer v0.1.39
[INFO] [stderr]    Compiling cpal v0.4.5
[INFO] [stderr]    Compiling serde_derive v1.0.15
[INFO] [stderr]    Compiling num v0.2.0
[INFO] [stderr]    Compiling synthrs v0.1.0 (https://github.com/gyng/synthrs?rev=a067f2bee46e5f8593003dc4ad5b6df97bdb3898#a067f2be)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/git/checkouts/synthrs-a4b8c03c849616c3/a067f2b/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` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "d23bf9caea4b4ebc4fded13bc774231f0147e290180a2a0b44698257790bcb53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d23bf9caea4b4ebc4fded13bc774231f0147e290180a2a0b44698257790bcb53", kill_on_drop: false }`
[INFO] [stdout] d23bf9caea4b4ebc4fded13bc774231f0147e290180a2a0b44698257790bcb53