[INFO] fetching crate semester 1.0.3...
[INFO] building semester-1.0.3 against master#c7f6aa2869acdbf014d094c6e427e554e160b6db for pr-146237-2
[INFO] extracting crate semester 1.0.3 into /workspace/builds/worker-3-tc1/source
[INFO] started tweaking crates.io crate semester 1.0.3
[INFO] finished tweaking crates.io crate semester 1.0.3
[INFO] tweaked toml for crates.io crate semester 1.0.3 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate semester 1.0.3 on toolchain c7f6aa2869acdbf014d094c6e427e554e160b6db
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 10 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded joinery v3.1.0
[INFO] [stderr]   Downloaded semester-macro v2.0.2
[INFO] [stderr]   Downloaded indent_write v2.2.0
[INFO] [stderr]   Downloaded cool_asserts v2.0.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cd8a13f6b79b0d96b661b333f7dbfd032654449fe873eccae85806d0fd54c814
[INFO] running `Command { std: "docker" "start" "-a" "cd8a13f6b79b0d96b661b333f7dbfd032654449fe873eccae85806d0fd54c814", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cd8a13f6b79b0d96b661b333f7dbfd032654449fe873eccae85806d0fd54c814", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd8a13f6b79b0d96b661b333f7dbfd032654449fe873eccae85806d0fd54c814", kill_on_drop: false }`
[INFO] [stdout] cd8a13f6b79b0d96b661b333f7dbfd032654449fe873eccae85806d0fd54c814
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3bc16f11721c1da822db64248940d70414ded4f28223a4e35c175d1f3b6dfd6d
[INFO] running `Command { std: "docker" "start" "-a" "3bc16f11721c1da822db64248940d70414ded4f28223a4e35c175d1f3b6dfd6d", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.101
[INFO] [stderr]    Compiling unicode-ident v1.0.19
[INFO] [stderr]    Compiling quote v1.0.41
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling either v1.15.0
[INFO] [stderr]    Compiling joinery v3.1.0
[INFO] [stderr]    Compiling itertools v0.10.5
[INFO] [stderr]    Compiling semester-macro v2.0.2
[INFO] [stderr]    Compiling semester v1.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:290:5
[INFO] [stdout]     |
[INFO] [stdout] 290 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:297:5
[INFO] [stdout]     |
[INFO] [stdout] 297 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:303:5
[INFO] [stdout]     |
[INFO] [stdout] 303 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:309:5
[INFO] [stdout]     |
[INFO] [stdout] 309 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:346:5
[INFO] [stdout]     |
[INFO] [stdout] 346 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:352:5
[INFO] [stdout]     |
[INFO] [stdout] 352 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 7.75s
[INFO] running `Command { std: "docker" "inspect" "3bc16f11721c1da822db64248940d70414ded4f28223a4e35c175d1f3b6dfd6d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3bc16f11721c1da822db64248940d70414ded4f28223a4e35c175d1f3b6dfd6d", kill_on_drop: false }`
[INFO] [stdout] 3bc16f11721c1da822db64248940d70414ded4f28223a4e35c175d1f3b6dfd6d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 98557212ea3e8af84a53d2d0b4c2efe4a26a91dce116d7a3f2f0db5d168b014d
[INFO] running `Command { std: "docker" "start" "-a" "98557212ea3e8af84a53d2d0b4c2efe4a26a91dce116d7a3f2f0db5d168b014d", kill_on_drop: false }`
[INFO] [stderr]    Compiling indent_write v2.2.0
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:290:5
[INFO] [stdout]     |
[INFO] [stdout] 290 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:297:5
[INFO] [stdout]     |
[INFO] [stdout] 297 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:303:5
[INFO] [stdout]     |
[INFO] [stdout] 303 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:309:5
[INFO] [stdout]     |
[INFO] [stdout] 309 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:346:5
[INFO] [stdout]     |
[INFO] [stdout] 346 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:352:5
[INFO] [stdout]     |
[INFO] [stdout] 352 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling cool_asserts v2.0.3
[INFO] [stderr]    Compiling semester v1.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:290:5
[INFO] [stdout]     |
[INFO] [stdout] 290 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:297:5
[INFO] [stdout]     |
[INFO] [stdout] 297 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:303:5
[INFO] [stdout]     |
[INFO] [stdout] 303 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:309:5
[INFO] [stdout]     |
[INFO] [stdout] 309 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:346:5
[INFO] [stdout]     |
[INFO] [stdout] 346 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/lib.rs:352:5
[INFO] [stdout]     |
[INFO] [stdout] 352 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, functions, unions, required trait methods, provided trait methods, inherent methods, foreign functions, and traits
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 1.25s
[INFO] running `Command { std: "docker" "inspect" "98557212ea3e8af84a53d2d0b4c2efe4a26a91dce116d7a3f2f0db5d168b014d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "98557212ea3e8af84a53d2d0b4c2efe4a26a91dce116d7a3f2f0db5d168b014d", kill_on_drop: false }`
[INFO] [stdout] 98557212ea3e8af84a53d2d0b4c2efe4a26a91dce116d7a3f2f0db5d168b014d