[INFO] fetching crate diff_fmt 0.1.0...
[INFO] testing diff_fmt-0.1.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate diff_fmt 0.1.0 into /workspace/builds/worker-35/source
[INFO] validating manifest of crates.io crate diff_fmt 0.1.0 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] removed /workspace/builds/worker-35/source/rust-toolchain
[INFO] started tweaking crates.io crate diff_fmt 0.1.0
[INFO] finished tweaking crates.io crate diff_fmt 0.1.0
[INFO] tweaked toml for crates.io crate diff_fmt 0.1.0 written to /workspace/builds/worker-35/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/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] 9a9407dc0d62abba28e794d4c392cab274a1acac85dfb84fbac1fb3271025408
[INFO] running `Command { std: "docker" "start" "-a" "9a9407dc0d62abba28e794d4c392cab274a1acac85dfb84fbac1fb3271025408", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9a9407dc0d62abba28e794d4c392cab274a1acac85dfb84fbac1fb3271025408", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a9407dc0d62abba28e794d4c392cab274a1acac85dfb84fbac1fb3271025408", kill_on_drop: false }`
[INFO] [stdout] 9a9407dc0d62abba28e794d4c392cab274a1acac85dfb84fbac1fb3271025408
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-35/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] 58e343bf6d7f042ca7249bf15bb112cce414b807719261c2b2fd4372cb70b636
[INFO] running `Command { std: "docker" "start" "-a" "58e343bf6d7f042ca7249bf15bb112cce414b807719261c2b2fd4372cb70b636", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling numtoa v0.1.0
[INFO] [stderr]    Compiling termion v1.5.6
[INFO] [stderr]    Compiling diff_fmt v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0433]: failed to resolve: could not find `Position` in `v1`
[INFO] [stdout]   --> src/lib.rs:40:40
[INFO] [stdout]    |
[INFO] [stdout] 40 |         position: ::core::fmt::rt::v1::Position::At(0usize),
[INFO] [stdout]    |                                        ^^^^^^^^ could not find `Position` in `v1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:17:1
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(prelude_import)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:18:1
[INFO] [stdout]    |
[INFO] [stdout] 18 | #![feature(print_internals)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:19:1
[INFO] [stdout]    |
[INFO] [stdout] 19 | #![feature(fmt_internals)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0433, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0433`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `diff_fmt` due to 5 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "58e343bf6d7f042ca7249bf15bb112cce414b807719261c2b2fd4372cb70b636", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "58e343bf6d7f042ca7249bf15bb112cce414b807719261c2b2fd4372cb70b636", kill_on_drop: false }`
[INFO] [stdout] 58e343bf6d7f042ca7249bf15bb112cce414b807719261c2b2fd4372cb70b636