[INFO] fetching crate knights-tour 0.0.0...
[INFO] testing knights-tour-0.0.0 against 1.75.0 for beta-1.76-1
[INFO] extracting crate knights-tour 0.0.0 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate knights-tour 0.0.0 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate knights-tour 0.0.0
[INFO] finished tweaking crates.io crate knights-tour 0.0.0
[INFO] tweaked toml for crates.io crate knights-tour 0.0.0 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e826481b0e787462d8b798824dd1cf43d660ecdae0e4d8388d90d126ea9c461c
[INFO] running `Command { std: "docker" "start" "-a" "e826481b0e787462d8b798824dd1cf43d660ecdae0e4d8388d90d126ea9c461c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e826481b0e787462d8b798824dd1cf43d660ecdae0e4d8388d90d126ea9c461c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e826481b0e787462d8b798824dd1cf43d660ecdae0e4d8388d90d126ea9c461c", kill_on_drop: false }`
[INFO] [stdout] e826481b0e787462d8b798824dd1cf43d660ecdae0e4d8388d90d126ea9c461c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b7c90b3334dfc16c363b7e499debddd0b75e3f4a8da6b4951e304ab19291049d
[INFO] running `Command { std: "docker" "start" "-a" "b7c90b3334dfc16c363b7e499debddd0b75e3f4a8da6b4951e304ab19291049d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.151
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling ppv-lite86 v0.2.17
[INFO] [stderr]    Compiling svg v0.13.1
[INFO] [stderr]    Compiling getrandom v0.2.11
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling knights-tour v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(generators)]
[INFO] [stdout]   |            ^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: renamed to `coroutines`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::iter::from_generator`
[INFO] [stdout]  --> src/states/mod.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     iter::from_generator,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^ no `from_generator` in `iter`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(generators)]
[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:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(iter_from_generator)]
[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:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(type_alias_impl_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/states/solve_tour.rs:66:21
[INFO] [stdout]    |
[INFO] [stdout] 66 |                     yield state;
[INFO] [stdout]    |                     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/states/solve_tour.rs:70:21
[INFO] [stdout]    |
[INFO] [stdout] 70 |                     yield state;
[INFO] [stdout]    |                     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/states/solve_tour.rs:120:17
[INFO] [stdout]     |
[INFO] [stdout] 120 |                 yield state;
[INFO] [stdout]     |                 ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: `impl Trait` in associated types is unstable
[INFO] [stdout]   --> src/roles/mod.rs:63:21
[INFO] [stdout]    |
[INFO] [stdout] 63 |     type IntoIter = impl Iterator<Item = Self::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:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(iter_from_generator)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `iter_from_generator`
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(iter_from_generator)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 11 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554, E0557, E0635, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `knights-tour` (lib) due to 12 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "b7c90b3334dfc16c363b7e499debddd0b75e3f4a8da6b4951e304ab19291049d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b7c90b3334dfc16c363b7e499debddd0b75e3f4a8da6b4951e304ab19291049d", kill_on_drop: false }`
[INFO] [stdout] b7c90b3334dfc16c363b7e499debddd0b75e3f4a8da6b4951e304ab19291049d
