[INFO] fetching crate puroro 0.1.3...
[INFO] checking puroro-0.1.3 against 1.55.0 for beta-1.56-3
[INFO] extracting crate puroro 0.1.3 into /workspace/builds/worker-21/source
[INFO] validating manifest of crates.io crate puroro 0.1.3 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 crates.io crate puroro 0.1.3
[INFO] finished tweaking crates.io crate puroro 0.1.3
[INFO] tweaked toml for crates.io crate puroro 0.1.3 written to /workspace/builds/worker-21/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-21/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/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] ec6cc3294aec3bd6e82ec206df5342ff5ae15ae3d252c72eb3401f6597ddbecf
[INFO] running `Command { std: "docker" "start" "-a" "ec6cc3294aec3bd6e82ec206df5342ff5ae15ae3d252c72eb3401f6597ddbecf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ec6cc3294aec3bd6e82ec206df5342ff5ae15ae3d252c72eb3401f6597ddbecf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ec6cc3294aec3bd6e82ec206df5342ff5ae15ae3d252c72eb3401f6597ddbecf", kill_on_drop: false }`
[INFO] [stdout] ec6cc3294aec3bd6e82ec206df5342ff5ae15ae3d252c72eb3401f6597ddbecf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/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" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 31b3628530bcca540983353f45b83cfc4cde520266f4611a270f24be1cea24ec
[INFO] running `Command { std: "docker" "start" "-a" "31b3628530bcca540983353f45b83cfc4cde520266f4611a270f24be1cea24ec", kill_on_drop: false }`
[INFO] [stderr]    Compiling thiserror-impl v1.0.30
[INFO] [stderr]    Compiling num-derive v0.3.3
[INFO] [stderr]     Checking thiserror v1.0.30
[INFO] [stderr]     Checking puroro v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> src/lib.rs:201:1
[INFO] [stdout]     |
[INFO] [stdout] 201 | #![feature(backtrace)]
[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:202:1
[INFO] [stdout]     |
[INFO] [stdout] 202 | #![feature(generic_associated_types)]
[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:203:1
[INFO] [stdout]     |
[INFO] [stdout] 203 | #![feature(type_alias_impl_trait)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: `impl Trait` in type aliases is unstable
[INFO] [stdout]   --> src/internal/impls/merged.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |         impl Iterator<Item = Either<<T as IntoIterator>::Item, <U as IntoIterator>::Item>>;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: `impl Trait` in type aliases is unstable
[INFO] [stdout]   --> src/internal/impls/merged.rs:74:9
[INFO] [stdout]    |
[INFO] [stdout] 74 |         impl Iterator<Item = Either<<T as IntoIterator>::Item, <U as IntoIterator>::Item>>;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> src/lib.rs:201:1
[INFO] [stdout]     |
[INFO] [stdout] 201 | #![feature(backtrace)]
[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:202:1
[INFO] [stdout]     |
[INFO] [stdout] 202 | #![feature(generic_associated_types)]
[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:203:1
[INFO] [stdout]     |
[INFO] [stdout] 203 | #![feature(type_alias_impl_trait)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: `impl Trait` in type aliases is unstable
[INFO] [stdout]   --> src/internal/impls/merged.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |         impl Iterator<Item = Either<<T as IntoIterator>::Item, <U as IntoIterator>::Item>>;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: `impl Trait` in type aliases is unstable
[INFO] [stdout]   --> src/internal/impls/merged.rs:74:9
[INFO] [stdout]    |
[INFO] [stdout] 74 |         impl Iterator<Item = Either<<T as IntoIterator>::Item, <U as IntoIterator>::Item>>;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0658.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `puroro` due to 6 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "31b3628530bcca540983353f45b83cfc4cde520266f4611a270f24be1cea24ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31b3628530bcca540983353f45b83cfc4cde520266f4611a270f24be1cea24ec", kill_on_drop: false }`
[INFO] [stdout] 31b3628530bcca540983353f45b83cfc4cde520266f4611a270f24be1cea24ec
