[INFO] cloning repository https://github.com/thejohncrafter/Verifier
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/thejohncrafter/Verifier" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthejohncrafter%2FVerifier", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthejohncrafter%2FVerifier'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bfb6d77dec965c06f633e9a62be21dce8b6416ce
[INFO] checking thejohncrafter/Verifier against beta-2021-10-15 for beta-1.56-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthejohncrafter%2FVerifier" "/workspace/builds/worker-34/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-34/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/thejohncrafter/Verifier on toolchain beta-2021-10-15
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-10-15" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/thejohncrafter/Verifier
[INFO] finished tweaking git repo https://github.com/thejohncrafter/Verifier
[INFO] tweaked toml for git repo https://github.com/thejohncrafter/Verifier written to /workspace/builds/worker-34/source/Cargo.toml
[INFO] crate git repo https://github.com/thejohncrafter/Verifier already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-10-15" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded notify v5.0.0-pre.1
[INFO] [stderr]   Downloaded wasm-bindgen-macro-support v0.2.53
[INFO] [stderr]   Downloaded wasm-bindgen-macro v0.2.53
[INFO] [stderr]   Downloaded chashmap v2.2.2
[INFO] [stderr]   Downloaded wasm-bindgen-backend v0.2.53
[INFO] [stderr]   Downloaded wasm-bindgen v0.2.53
[INFO] [stderr]   Downloaded wasm-bindgen-shared v0.2.53
[INFO] [stderr]   Downloaded smallvec v0.6.11
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/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" "+beta-2021-10-15" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 34889194b13ba924d6776dcca9c1cd8ecfff32b35f0695b50c5364c596fea337
[INFO] running `Command { std: "docker" "start" "-a" "34889194b13ba924d6776dcca9c1cd8ecfff32b35f0695b50c5364c596fea337", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "34889194b13ba924d6776dcca9c1cd8ecfff32b35f0695b50c5364c596fea337", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34889194b13ba924d6776dcca9c1cd8ecfff32b35f0695b50c5364c596fea337", kill_on_drop: false }`
[INFO] [stdout] 34889194b13ba924d6776dcca9c1cd8ecfff32b35f0695b50c5364c596fea337
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/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" "+beta-2021-10-15" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4c876ff8813dac7a4ddf7907a5071a273c9c0d7a6849dcdb4a36a384a2ebb935
[INFO] running `Command { std: "docker" "start" "-a" "4c876ff8813dac7a4ddf7907a5071a273c9c0d7a6849dcdb4a36a384a2ebb935", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.53
[INFO] [stderr]    Compiling syn v1.0.7
[INFO] [stderr]    Compiling bumpalo v2.6.0
[INFO] [stderr]     Checking smallvec v0.6.11
[INFO] [stderr]     Checking stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling wasm-bindgen v0.2.53
[INFO] [stderr]     Checking same-file v1.0.5
[INFO] [stderr]     Checking anymap v0.12.1
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking filetime v0.2.7
[INFO] [stderr]     Checking walkdir v2.2.9
[INFO] [stderr]     Checking owning_ref v0.3.3
[INFO] [stderr]     Checking inotify v0.7.0
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking parking_lot_core v0.2.14
[INFO] [stderr]     Checking parking_lot v0.4.8
[INFO] [stderr]     Checking chashmap v2.2.2
[INFO] [stderr]     Checking mio-extras v2.0.5
[INFO] [stderr]     Checking notify v5.0.0-pre.1
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.53
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.53
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.53
[INFO] [stderr]     Checking tipe v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:36:22
[INFO] [stdout]    |
[INFO] [stdout] 36 |     fn format(&self, &mut dyn Write) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(anonymous_parameters)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:40:22
[INFO] [stdout]    |
[INFO] [stdout] 40 |     fn format(&self, &mut dyn Write, &dyn VarTemplate, &Term) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:40:38
[INFO] [stdout]    |
[INFO] [stdout] 40 |     fn format(&self, &mut dyn Write, &dyn VarTemplate, &Term) -> Result;
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &dyn VarTemplate`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:40:56
[INFO] [stdout]    |
[INFO] [stdout] 40 |     fn format(&self, &mut dyn Write, &dyn VarTemplate, &Term) -> Result;
[INFO] [stdout]    |                                                        ^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Term`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:44:22
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:44:38
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Vec<Box<Term>>`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:48:22
[INFO] [stdout]    |
[INFO] [stdout] 48 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:48:38
[INFO] [stdout]    |
[INFO] [stdout] 48 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Vec<Box<Term>>`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:36:22
[INFO] [stdout]    |
[INFO] [stdout] 36 |     fn format(&self, &mut dyn Write) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(anonymous_parameters)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:40:22
[INFO] [stdout]    |
[INFO] [stdout] 40 |     fn format(&self, &mut dyn Write, &dyn VarTemplate, &Term) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:40:38
[INFO] [stdout]    |
[INFO] [stdout] 40 |     fn format(&self, &mut dyn Write, &dyn VarTemplate, &Term) -> Result;
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &dyn VarTemplate`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:40:56
[INFO] [stdout]    |
[INFO] [stdout] 40 |     fn format(&self, &mut dyn Write, &dyn VarTemplate, &Term) -> Result;
[INFO] [stdout]    |                                                        ^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Term`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:44:22
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:44:38
[INFO] [stdout]    |
[INFO] [stdout] 44 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Vec<Box<Term>>`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:48:22
[INFO] [stdout]    |
[INFO] [stdout] 48 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &mut dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: anonymous parameters are deprecated and will be removed in the next edition.
[INFO] [stdout]   --> src/core/base_types.rs:48:38
[INFO] [stdout]    |
[INFO] [stdout] 48 |     fn format(&self, &mut dyn Write, &Vec<Box<Term>>) -> Result;
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Vec<Box<Term>>`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
[INFO] [stdout]    = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a closure that returns `Result`
[INFO] [stdout]    --> src/core/matcher.rs:296:55
[INFO] [stdout]     |
[INFO] [stdout] 295 |                   args.iter().try_for_each(|p| {
[INFO] [stdout]     |  __________________________________________-
[INFO] [stdout] 296 | |                     built_args.push(self.build_term(p)?);
[INFO] [stdout]     | |                                                       ^ use `.ok_or(...)?` to provide an error compatible with `std::result::Result<(), _>`
[INFO] [stdout] 297 | |                     Ok(())
[INFO] [stdout] 298 | |                 })?;
[INFO] [stdout]     | |_________________- this function returns a `Result`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `std::result::Result<(), _>`
[INFO] [stdout] note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Option`s, not `Result`s, in a method that returns `Option`
[INFO] [stdout]    --> src/core/matcher.rs:298:19
[INFO] [stdout]     |
[INFO] [stdout] 270 | /     fn build_term(&self, pattern: &TermPattern) -> Option<Box<Term>> {
[INFO] [stdout] 271 | |         match pattern {
[INFO] [stdout] 272 | |             TermPattern::Meta(name) => {
[INFO] [stdout] 273 | |                 if let Some(t) = self.meta_terms.get(name) {
[INFO] [stdout] ...   |
[INFO] [stdout] 298 | |                 })?;
[INFO] [stdout]     | |                   ^ use `.ok()?` if you want to discard the `std::result::Result<Infallible, _>` error information
[INFO] [stdout] ...   |
[INFO] [stdout] 312 | |         }
[INFO] [stdout] 313 | |     }
[INFO] [stdout]     | |_____- this function returns an `Option`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<std::result::Result<Infallible, _>>` is not implemented for `Option<Box<base_types::Term>>`
[INFO] [stdout] note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a closure that returns `Result`
[INFO] [stdout]    --> src/core/matcher.rs:296:55
[INFO] [stdout]     |
[INFO] [stdout] 295 |                   args.iter().try_for_each(|p| {
[INFO] [stdout]     |  __________________________________________-
[INFO] [stdout] 296 | |                     built_args.push(self.build_term(p)?);
[INFO] [stdout]     | |                                                       ^ use `.ok_or(...)?` to provide an error compatible with `std::result::Result<(), _>`
[INFO] [stdout] 297 | |                     Ok(())
[INFO] [stdout] 298 | |                 })?;
[INFO] [stdout]     | |_________________- this function returns a `Result`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `std::result::Result<(), _>`
[INFO] [stdout] note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Option`s, not `Result`s, in a method that returns `Option`
[INFO] [stdout]    --> src/core/matcher.rs:298:19
[INFO] [stdout]     |
[INFO] [stdout] 270 | /     fn build_term(&self, pattern: &TermPattern) -> Option<Box<Term>> {
[INFO] [stdout] 271 | |         match pattern {
[INFO] [stdout] 272 | |             TermPattern::Meta(name) => {
[INFO] [stdout] 273 | |                 if let Some(t) = self.meta_terms.get(name) {
[INFO] [stdout] ...   |
[INFO] [stdout] 298 | |                 })?;
[INFO] [stdout]     | |                   ^ use `.ok()?` if you want to discard the `std::result::Result<Infallible, _>` error information
[INFO] [stdout] ...   |
[INFO] [stdout] 312 | |         }
[INFO] [stdout] 313 | |     }
[INFO] [stdout]     | |_____- this function returns an `Option`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<std::result::Result<Infallible, _>>` is not implemented for `Option<Box<base_types::Term>>`
[INFO] [stdout] note: required by `from_residual`
[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 E0277`.
[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 E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tipe` due to 3 previous errors; 8 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "4c876ff8813dac7a4ddf7907a5071a273c9c0d7a6849dcdb4a36a384a2ebb935", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4c876ff8813dac7a4ddf7907a5071a273c9c0d7a6849dcdb4a36a384a2ebb935", kill_on_drop: false }`
[INFO] [stdout] 4c876ff8813dac7a4ddf7907a5071a273c9c0d7a6849dcdb4a36a384a2ebb935
