[INFO] fetching crate problem_generator 0.3.0...
[INFO] checking problem_generator-0.3.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] extracting crate problem_generator 0.3.0 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate problem_generator 0.3.0 on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate problem_generator 0.3.0
[INFO] finished tweaking crates.io crate problem_generator 0.3.0
[INFO] tweaked toml for crates.io crate problem_generator 0.3.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate crates.io crate problem_generator 0.3.0 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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded ron v0.6.6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3006f1e42b7a75485558401dd0ca914fa9f0a6863295321990a656f2e755ae9b
[INFO] running `Command { std: "docker" "start" "-a" "3006f1e42b7a75485558401dd0ca914fa9f0a6863295321990a656f2e755ae9b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3006f1e42b7a75485558401dd0ca914fa9f0a6863295321990a656f2e755ae9b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3006f1e42b7a75485558401dd0ca914fa9f0a6863295321990a656f2e755ae9b", kill_on_drop: false }`
[INFO] [stdout] 3006f1e42b7a75485558401dd0ca914fa9f0a6863295321990a656f2e755ae9b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0037f65829e83af0ff0a3db257c2fbfe71237452586b78ae4267e8dce556be02
[INFO] running `Command { std: "docker" "start" "-a" "0037f65829e83af0ff0a3db257c2fbfe71237452586b78ae4267e8dce556be02", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.112
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling syn v1.0.84
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling serde_derive v1.0.132
[INFO] [stderr]    Compiling memoffset v0.6.5
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling serde v1.0.132
[INFO] [stderr]    Compiling quote v1.0.14
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]     Checking crossbeam-channel v0.5.1
[INFO] [stderr]     Checking crossbeam-deque v0.8.1
[INFO] [stderr]     Checking getrandom v0.2.3
[INFO] [stderr]     Checking num_cpus v1.13.1
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.4
[INFO] [stderr]     Checking console v0.15.0
[INFO] [stderr]     Checking env_logger v0.8.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]     Checking indicatif v0.15.0
[INFO] [stderr]     Checking structopt v0.3.25
[INFO] [stderr]     Checking ron v0.6.6
[INFO] [stderr]     Checking problem_generator v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `problem_generator` is imported redundantly
[INFO] [stdout]  --> tests/integration_test.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 | use problem_generator::{self, problem::problem_generation::{run_opt, ProblemOpt, ProblemCommand::ConfigurationFolder}};
[INFO] [stdout]   |                         ^^^^ the item `problem_generator` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.60s
[INFO] running `Command { std: "docker" "inspect" "0037f65829e83af0ff0a3db257c2fbfe71237452586b78ae4267e8dce556be02", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0037f65829e83af0ff0a3db257c2fbfe71237452586b78ae4267e8dce556be02", kill_on_drop: false }`
[INFO] [stdout] 0037f65829e83af0ff0a3db257c2fbfe71237452586b78ae4267e8dce556be02
[INFO] checking problem_generator-0.3.0 against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] extracting crate problem_generator 0.3.0 into /workspace/builds/worker-0-tc2/source
[INFO] validating manifest of crates.io crate problem_generator 0.3.0 on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate problem_generator 0.3.0
[INFO] finished tweaking crates.io crate problem_generator 0.3.0
[INFO] tweaked toml for crates.io crate problem_generator 0.3.0 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate crates.io crate problem_generator 0.3.0 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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9b48a77d0f26cd05b960c7478d30704965281c4e989ab882b25b39e2ce79c159
[INFO] running `Command { std: "docker" "start" "-a" "9b48a77d0f26cd05b960c7478d30704965281c4e989ab882b25b39e2ce79c159", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9b48a77d0f26cd05b960c7478d30704965281c4e989ab882b25b39e2ce79c159", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9b48a77d0f26cd05b960c7478d30704965281c4e989ab882b25b39e2ce79c159", kill_on_drop: false }`
[INFO] [stdout] 9b48a77d0f26cd05b960c7478d30704965281c4e989ab882b25b39e2ce79c159
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ffefce5bc299d38ccaa29d6c97ab6be3147271f8ee1d96653a0d0c80d1a7210d
[INFO] running `Command { std: "docker" "start" "-a" "ffefce5bc299d38ccaa29d6c97ab6be3147271f8ee1d96653a0d0c80d1a7210d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.112
[INFO] [stderr]    Compiling syn v1.0.84
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling serde_derive v1.0.132
[INFO] [stderr]    Compiling memoffset v0.6.5
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling serde v1.0.132
[INFO] [stderr]    Compiling quote v1.0.14
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]     Checking crossbeam-channel v0.5.1
[INFO] [stderr]     Checking crossbeam-deque v0.8.1
[INFO] [stderr]     Checking getrandom v0.2.3
[INFO] [stderr]     Checking num_cpus v1.13.1
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.4
[INFO] [stderr]     Checking console v0.15.0
[INFO] [stderr]     Checking env_logger v0.8.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]     Checking indicatif v0.15.0
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]     Checking structopt v0.3.25
[INFO] [stderr]     Checking ron v0.6.6
[INFO] [stderr]     Checking problem_generator v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `problem_generator` is imported redundantly
[INFO] [stdout]  --> tests/integration_test.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 | use problem_generator::{self, problem::problem_generation::{run_opt, ProblemOpt, ProblemCommand::ConfigurationFolder}};
[INFO] [stdout]   |                         ^^^^ the item `problem_generator` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 18.38s
[INFO] running `Command { std: "docker" "inspect" "ffefce5bc299d38ccaa29d6c97ab6be3147271f8ee1d96653a0d0c80d1a7210d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ffefce5bc299d38ccaa29d6c97ab6be3147271f8ee1d96653a0d0c80d1a7210d", kill_on_drop: false }`
[INFO] [stdout] ffefce5bc299d38ccaa29d6c97ab6be3147271f8ee1d96653a0d0c80d1a7210d