[INFO] cloning repository https://github.com/conundrumer/crossword
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/conundrumer/crossword" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconundrumer%2Fcrossword", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconundrumer%2Fcrossword'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cec0ee1cc7277c14c4afeb48fc9488b7fa941ab3
[INFO] checking conundrumer/crossword against 1.55.0 for beta-1.56-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconundrumer%2Fcrossword" "/workspace/builds/worker-100/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-100/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/conundrumer/crossword 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/conundrumer/crossword
[INFO] finished tweaking git repo https://github.com/conundrumer/crossword
[INFO] tweaked toml for git repo https://github.com/conundrumer/crossword written to /workspace/builds/worker-100/source/Cargo.toml
[INFO] crate git repo https://github.com/conundrumer/crossword 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]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-100/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-100/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] dfeccc3d27fbfea57759680fd165facddd3a032f09368038c7a55e73411414d6
[INFO] running `Command { std: "docker" "start" "-a" "dfeccc3d27fbfea57759680fd165facddd3a032f09368038c7a55e73411414d6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dfeccc3d27fbfea57759680fd165facddd3a032f09368038c7a55e73411414d6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dfeccc3d27fbfea57759680fd165facddd3a032f09368038c7a55e73411414d6", kill_on_drop: false }`
[INFO] [stdout] dfeccc3d27fbfea57759680fd165facddd3a032f09368038c7a55e73411414d6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-100/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-100/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] a9438052d59cca128a00c5397d81fe90c0c9b2df30f726e4fd183f576b1dc65f
[INFO] running `Command { std: "docker" "start" "-a" "a9438052d59cca128a00c5397d81fe90c0c9b2df30f726e4fd183f576b1dc65f", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking crossword 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(conservative_impl_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `conservative_impl_trait` has been stable since 1.26.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around function argument
[INFO] [stdout]   --> src/grid.rs:25:21
[INFO] [stdout]    |
[INFO] [stdout] 25 |         vec![Empty; ((bb.width() as usize) * (bb.height() as usize))]
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:41:38
[INFO] [stdout]    |
[INFO] [stdout] 41 |     pub fn iter<'b>(&'b self) -> Box<Iterator<Item=Crossword> + 'b> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=Crossword> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:46:62
[INFO] [stdout]    |
[INFO] [stdout] 46 |     pub fn multi_iter<'b>(&'b self, num_iters: usize) -> Box<Iterator<Item=Crossword> + 'b> {
[INFO] [stdout]    |                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=Crossword> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:78:112
[INFO] [stdout]    |
[INFO] [stdout] 78 | ... -> Box<Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:89:114
[INFO] [stdout]    |
[INFO] [stdout] 89 | ...size>>, seed: u64) -> Box<Iterator<Item=Crossword> + 'b> {
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=Crossword> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/generate.rs:100:104
[INFO] [stdout]     |
[INFO] [stdout] 100 | ... -> Box<Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b> {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[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(conservative_impl_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `conservative_impl_trait` has been stable since 1.26.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around function argument
[INFO] [stdout]   --> src/grid.rs:25:21
[INFO] [stdout]    |
[INFO] [stdout] 25 |         vec![Empty; ((bb.width() as usize) * (bb.height() as usize))]
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:41:38
[INFO] [stdout]    |
[INFO] [stdout] 41 |     pub fn iter<'b>(&'b self) -> Box<Iterator<Item=Crossword> + 'b> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=Crossword> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:46:62
[INFO] [stdout]    |
[INFO] [stdout] 46 |     pub fn multi_iter<'b>(&'b self, num_iters: usize) -> Box<Iterator<Item=Crossword> + 'b> {
[INFO] [stdout]    |                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=Crossword> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:78:112
[INFO] [stdout]    |
[INFO] [stdout] 78 | ... -> Box<Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/generate.rs:89:114
[INFO] [stdout]    |
[INFO] [stdout] 89 | ...size>>, seed: u64) -> Box<Iterator<Item=Crossword> + 'b> {
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=Crossword> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/generate.rs:100:104
[INFO] [stdout]     |
[INFO] [stdout] 100 | ... -> Box<Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b> {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item=(Crossword, Rc<Vec<usize>>)> + 'b`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/generate.rs:187:73
[INFO] [stdout]     |
[INFO] [stdout] 187 |     pub fn test_generator(words: Vec<&str>, num_areas: usize, test_fn: &Fn(Generator) -> ()) {
[INFO] [stdout]     |                                                                         ^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(Generator) -> ()`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: an associated function with this name may be added to the standard library in the future
[INFO] [stdout]   --> src/filter.rs:32:57
[INFO] [stdout]    |
[INFO] [stdout] 32 |                 if let Some(area) = cell_areas.borrow().last() {
[INFO] [stdout]    |                                                         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unstable_name_collisions)]` on by default
[INFO] [stdout]    = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
[INFO] [stdout]    = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
[INFO] [stdout]    = help: call with fully qualified syntax `CollectionWithLast::last(...)` to keep using the current method
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: an associated function with this name may be added to the standard library in the future
[INFO] [stdout]   --> src/filter.rs:56:44
[INFO] [stdout]    |
[INFO] [stdout] 56 |             if let Some(last_area) = areas.last() {
[INFO] [stdout]    |                                            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
[INFO] [stdout]    = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
[INFO] [stdout]    = help: call with fully qualified syntax `CollectionWithLast::last(...)` to keep using the current method
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `crossword` due to 3 previous errors; 8 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: an associated function with this name may be added to the standard library in the future
[INFO] [stdout]   --> src/filter.rs:32:57
[INFO] [stdout]    |
[INFO] [stdout] 32 |                 if let Some(area) = cell_areas.borrow().last() {
[INFO] [stdout]    |                                                         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unstable_name_collisions)]` on by default
[INFO] [stdout]    = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
[INFO] [stdout]    = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
[INFO] [stdout]    = help: call with fully qualified syntax `CollectionWithLast::last(...)` to keep using the current method
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: an associated function with this name may be added to the standard library in the future
[INFO] [stdout]   --> src/filter.rs:56:44
[INFO] [stdout]    |
[INFO] [stdout] 56 |             if let Some(last_area) = areas.last() {
[INFO] [stdout]    |                                            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
[INFO] [stdout]    = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
[INFO] [stdout]    = help: call with fully qualified syntax `CollectionWithLast::last(...)` to keep using the current method
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a9438052d59cca128a00c5397d81fe90c0c9b2df30f726e4fd183f576b1dc65f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a9438052d59cca128a00c5397d81fe90c0c9b2df30f726e4fd183f576b1dc65f", kill_on_drop: false }`
[INFO] [stdout] a9438052d59cca128a00c5397d81fe90c0c9b2df30f726e4fd183f576b1dc65f
