[INFO] cloning repository https://github.com/openstax-poland/gitpub
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/openstax-poland/gitpub" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fopenstax-poland%2Fgitpub", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fopenstax-poland%2Fgitpub'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ad9298f763fca2d611c2e07fa3cfe75266166a74
[INFO] testing openstax-poland/gitpub against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fopenstax-poland%2Fgitpub" "/workspace/builds/worker-61/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-61/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/openstax-poland/gitpub 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/openstax-poland/gitpub
[INFO] finished tweaking git repo https://github.com/openstax-poland/gitpub
[INFO] tweaked toml for git repo https://github.com/openstax-poland/gitpub written to /workspace/builds/worker-61/source/Cargo.toml
[INFO] crate git repo https://github.com/openstax-poland/gitpub 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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded filetime v0.2.15
[INFO] [stderr]   Downloaded git2 v0.13.21
[INFO] [stderr]   Downloaded libgit2-sys v0.12.22+1.1.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/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] 89b811391f02914cb9e7ce53d6300f002c18e5d140e96942586dbaa2f92499d0
[INFO] running `Command { std: "docker" "start" "-a" "89b811391f02914cb9e7ce53d6300f002c18e5d140e96942586dbaa2f92499d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "89b811391f02914cb9e7ce53d6300f002c18e5d140e96942586dbaa2f92499d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "89b811391f02914cb9e7ce53d6300f002c18e5d140e96942586dbaa2f92499d0", kill_on_drop: false }`
[INFO] [stdout] 89b811391f02914cb9e7ce53d6300f002c18e5d140e96942586dbaa2f92499d0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-61/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] e7342fd668fdb1b0a2259309fee8aaf9127b6dab3e9bff67a9995b9722104de4
[INFO] running `Command { std: "docker" "start" "-a" "e7342fd668fdb1b0a2259309fee8aaf9127b6dab3e9bff67a9995b9722104de4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling pkg-config v0.3.19
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.29
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling tinyvec_macros v0.1.0
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling matches v0.1.9
[INFO] [stderr]    Compiling unicode-bidi v0.3.6
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]    Compiling crc32fast v1.2.1
[INFO] [stderr]    Compiling percent-encoding v2.1.0
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling anyhow v1.0.43
[INFO] [stderr]    Compiling argh_shared v0.1.5
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling openssl-probe v0.1.4
[INFO] [stderr]    Compiling humantime v2.1.0
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling numtoa v0.1.0
[INFO] [stderr]    Compiling json v0.12.4
[INFO] [stderr]    Compiling tinyvec v1.3.1
[INFO] [stderr]    Compiling form_urlencoded v1.0.1
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling unicode-normalization v0.1.19
[INFO] [stderr]    Compiling jobserver v0.1.24
[INFO] [stderr]    Compiling filetime v0.2.15
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling xattr v0.2.2
[INFO] [stderr]    Compiling termion v1.5.6
[INFO] [stderr]    Compiling env_logger v0.9.0
[INFO] [stderr]    Compiling cc v1.0.70
[INFO] [stderr]    Compiling tar v0.4.37
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling idna v0.2.3
[INFO] [stderr]    Compiling flate2 v1.0.21
[INFO] [stderr]    Compiling libz-sys v1.1.3
[INFO] [stderr]    Compiling openssl-sys v0.9.66
[INFO] [stderr]    Compiling libssh2-sys v0.2.21
[INFO] [stderr]    Compiling libgit2-sys v0.12.22+1.1.0
[INFO] [stderr]    Compiling url v2.2.2
[INFO] [stderr]    Compiling argh_derive v0.1.5
[INFO] [stderr]    Compiling argh v0.1.5
[INFO] [stderr]    Compiling git2 v0.13.21
[INFO] [stderr]    Compiling gitpub v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.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 `gitpub` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "e7342fd668fdb1b0a2259309fee8aaf9127b6dab3e9bff67a9995b9722104de4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e7342fd668fdb1b0a2259309fee8aaf9127b6dab3e9bff67a9995b9722104de4", kill_on_drop: false }`
[INFO] [stdout] e7342fd668fdb1b0a2259309fee8aaf9127b6dab3e9bff67a9995b9722104de4