[INFO] cloning repository https://github.com/fisherdarling/nfamatch-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fisherdarling/nfamatch-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffisherdarling%2Fnfamatch-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffisherdarling%2Fnfamatch-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 26a6a4046ab42b25f9e21b77f2adbbdd48f380e9
[INFO] testing fisherdarling/nfamatch-rs against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffisherdarling%2Fnfamatch-rs" "/workspace/builds/worker-44/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-44/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fisherdarling/nfamatch-rs 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/fisherdarling/nfamatch-rs
[INFO] finished tweaking git repo https://github.com/fisherdarling/nfamatch-rs
[INFO] tweaked toml for git repo https://github.com/fisherdarling/nfamatch-rs written to /workspace/builds/worker-44/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-44/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-44/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] 4c0916a726d45d154e1b9d7e1b73d2142b01b4d2c10ab9e69556bbf6a7690f25
[INFO] running `Command { std: "docker" "start" "-a" "4c0916a726d45d154e1b9d7e1b73d2142b01b4d2c10ab9e69556bbf6a7690f25", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4c0916a726d45d154e1b9d7e1b73d2142b01b4d2c10ab9e69556bbf6a7690f25", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4c0916a726d45d154e1b9d7e1b73d2142b01b4d2c10ab9e69556bbf6a7690f25", kill_on_drop: false }`
[INFO] [stdout] 4c0916a726d45d154e1b9d7e1b73d2142b01b4d2c10ab9e69556bbf6a7690f25
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-44/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-44/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] 0d9b10fefd3d3a47a0dd081b03b9e5d10d2ee2891846aefab2d125a6583f72b2
[INFO] running `Command { std: "docker" "start" "-a" "0d9b10fefd3d3a47a0dd081b03b9e5d10d2ee2891846aefab2d125a6583f72b2", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.29
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling humantime v2.1.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling aho-corasick v0.7.18
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling env_logger v0.9.0
[INFO] [stderr]    Compiling structopt-derive v0.4.16
[INFO] [stderr]    Compiling structopt v0.3.23
[INFO] [stderr]    Compiling dfa-optimizer v0.1.0 (/opt/rustwide/workdir/dfa-optimizer)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> dfa-optimizer/./src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(map_first_last)]
[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 `dfa-optimizer` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "0d9b10fefd3d3a47a0dd081b03b9e5d10d2ee2891846aefab2d125a6583f72b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d9b10fefd3d3a47a0dd081b03b9e5d10d2ee2891846aefab2d125a6583f72b2", kill_on_drop: false }`
[INFO] [stdout] 0d9b10fefd3d3a47a0dd081b03b9e5d10d2ee2891846aefab2d125a6583f72b2