[INFO] fetching crate exam 0.0.3...
[INFO] checking exam-0.0.3 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate exam 0.0.3 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate exam 0.0.3 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate exam 0.0.3
[INFO] finished tweaking crates.io crate exam 0.0.3
[INFO] tweaked toml for crates.io crate exam 0.0.3 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate crates.io crate exam 0.0.3 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5e39b9ce2ca6e59b64b669bfbd6daad13c0ac42854db3818a4703e02e433d09e
[INFO] running `Command { std: "docker" "start" "-a" "5e39b9ce2ca6e59b64b669bfbd6daad13c0ac42854db3818a4703e02e433d09e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5e39b9ce2ca6e59b64b669bfbd6daad13c0ac42854db3818a4703e02e433d09e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e39b9ce2ca6e59b64b669bfbd6daad13c0ac42854db3818a4703e02e433d09e", kill_on_drop: false }`
[INFO] [stdout] 5e39b9ce2ca6e59b64b669bfbd6daad13c0ac42854db3818a4703e02e433d09e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b584529814c8541320941c04b18d1b1d4186854c5c92f9da15235dd605bf13c9
[INFO] running `Command { std: "docker" "start" "-a" "b584529814c8541320941c04b18d1b1d4186854c5c92f9da15235dd605bf13c9", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.38
[INFO] [stderr]    Compiling unicode-xid v0.2.3
[INFO] [stderr]    Compiling syn v1.0.94
[INFO] [stderr]     Checking downcast-rs v1.2.0
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]    Compiling thiserror-impl v1.0.31
[INFO] [stderr]     Checking thiserror v1.0.31
[INFO] [stderr]     Checking exam v0.0.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.39s
[INFO] running `Command { std: "docker" "inspect" "b584529814c8541320941c04b18d1b1d4186854c5c92f9da15235dd605bf13c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b584529814c8541320941c04b18d1b1d4186854c5c92f9da15235dd605bf13c9", kill_on_drop: false }`
[INFO] [stdout] b584529814c8541320941c04b18d1b1d4186854c5c92f9da15235dd605bf13c9
[INFO] checking exam-0.0.3 against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] extracting crate exam 0.0.3 into /workspace/builds/worker-6-tc2/source
[INFO] validating manifest of crates.io crate exam 0.0.3 on toolchain 3a4bc97f6385a3aa300a4fd689b44350e54fd676
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate exam 0.0.3
[INFO] finished tweaking crates.io crate exam 0.0.3
[INFO] tweaked toml for crates.io crate exam 0.0.3 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate crates.io crate exam 0.0.3 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 987e94075f32c071ff49922a241145f30a245a0e9756daad5c1e7f9d995ae8c4
[INFO] running `Command { std: "docker" "start" "-a" "987e94075f32c071ff49922a241145f30a245a0e9756daad5c1e7f9d995ae8c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "987e94075f32c071ff49922a241145f30a245a0e9756daad5c1e7f9d995ae8c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "987e94075f32c071ff49922a241145f30a245a0e9756daad5c1e7f9d995ae8c4", kill_on_drop: false }`
[INFO] [stdout] 987e94075f32c071ff49922a241145f30a245a0e9756daad5c1e7f9d995ae8c4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 96239756a5f77c95ed77d8cae08c823944b0b9fc6183465b204fa806d343b0ad
[INFO] running `Command { std: "docker" "start" "-a" "96239756a5f77c95ed77d8cae08c823944b0b9fc6183465b204fa806d343b0ad", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.38
[INFO] [stderr]    Compiling unicode-xid v0.2.3
[INFO] [stderr]    Compiling syn v1.0.94
[INFO] [stderr]     Checking downcast-rs v1.2.0
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]    Compiling thiserror-impl v1.0.31
[INFO] [stderr]     Checking thiserror v1.0.31
[INFO] [stderr]     Checking exam v0.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]   --> src/lib.rs:81:18
[INFO] [stdout]    |
[INFO] [stdout] 81 |                 .map_err(|_| panic!("This downcast shouldn't fail"))
[INFO] [stdout]    |                  ^^^^^^^ cannot infer type of the type parameter `F` declared on the method `map_err`
[INFO] [stdout]    |
[INFO] [stdout] help: consider specifying the generic arguments
[INFO] [stdout]    |
[INFO] [stdout] 81 |                 .map_err::<F, _>(|_| panic!("This downcast shouldn't fail"))
[INFO] [stdout]    |                         ++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]   --> src/lib.rs:81:18
[INFO] [stdout]    |
[INFO] [stdout] 81 |                 .map_err(|_| panic!("This downcast shouldn't fail"))
[INFO] [stdout]    |                  ^^^^^^^ cannot infer type of the type parameter `F` declared on the method `map_err`
[INFO] [stdout]    |
[INFO] [stdout] help: consider specifying the generic arguments
[INFO] [stdout]    |
[INFO] [stdout] 81 |                 .map_err::<F, _>(|_| panic!("This downcast shouldn't fail"))
[INFO] [stdout]    |                         ++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exam` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `exam` (lib test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "96239756a5f77c95ed77d8cae08c823944b0b9fc6183465b204fa806d343b0ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "96239756a5f77c95ed77d8cae08c823944b0b9fc6183465b204fa806d343b0ad", kill_on_drop: false }`
[INFO] [stdout] 96239756a5f77c95ed77d8cae08c823944b0b9fc6183465b204fa806d343b0ad