[INFO] fetching crate flexiber 0.1.1...
[INFO] checking flexiber-0.1.1 against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] extracting crate flexiber 0.1.1 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate flexiber 0.1.1 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 flexiber 0.1.1
[INFO] finished tweaking crates.io crate flexiber 0.1.1
[INFO] tweaked toml for crates.io crate flexiber 0.1.1 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 23 packages
[INFO] [stderr]       Adding hash32 v0.2.1 (latest: v0.3.1)
[INFO] [stderr]       Adding heapless v0.7.17 (latest: v0.8.0)
[INFO] [stderr]       Adding hex-literal v0.3.4 (latest: v0.4.1)
[INFO] [stderr]       Adding syn v1.0.109 (latest: v2.0.58)
[INFO] [stderr]       Adding synstructure v0.12.6 (latest: v0.13.1)
[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 flexiber_derive v0.1.0
[INFO] [stderr]   Downloaded delog v0.1.7
[INFO] [stderr]   Downloaded heapless v0.7.17
[INFO] [stderr]   Downloaded atomic-polyfill v1.0.3
[INFO] [stderr]   Downloaded hex-literal v0.3.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 4ab7b76323b4b2f3dfce48bb0bd42703e1beec3eeb28c7a2a2fe642e1c30ba9f
[INFO] running `Command { std: "docker" "start" "-a" "4ab7b76323b4b2f3dfce48bb0bd42703e1beec3eeb28c7a2a2fe642e1c30ba9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4ab7b76323b4b2f3dfce48bb0bd42703e1beec3eeb28c7a2a2fe642e1c30ba9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4ab7b76323b4b2f3dfce48bb0bd42703e1beec3eeb28c7a2a2fe642e1c30ba9f", kill_on_drop: false }`
[INFO] [stdout] 4ab7b76323b4b2f3dfce48bb0bd42703e1beec3eeb28c7a2a2fe642e1c30ba9f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] fb43dbdf7f32b227e2926d4b32ec2ac00c5c4a69fc63c8eaf90fedb804039f4a
[INFO] running `Command { std: "docker" "start" "-a" "fb43dbdf7f32b227e2926d4b32ec2ac00c5c4a69fc63c8eaf90fedb804039f4a", kill_on_drop: false }`
[INFO] [stderr]    Compiling delog v0.1.7
[INFO] [stderr]    Compiling hex-literal v0.3.4
[INFO] [stderr]     Checking flexiber v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait `Taggable` is never used
[INFO] [stdout]    --> src/traits.rs:162:18
[INFO] [stdout]     |
[INFO] [stdout] 162 | pub(crate) trait Taggable<T: TagLike>: Sized {
[INFO] [stdout]     |                  ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `T3` is never constructed
[INFO] [stdout]    --> src/traits.rs:568:12
[INFO] [stdout]     |
[INFO] [stdout] 568 |     struct T3 {
[INFO] [stdout]     |            ^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` 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 1.63s
[INFO] running `Command { std: "docker" "inspect" "fb43dbdf7f32b227e2926d4b32ec2ac00c5c4a69fc63c8eaf90fedb804039f4a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb43dbdf7f32b227e2926d4b32ec2ac00c5c4a69fc63c8eaf90fedb804039f4a", kill_on_drop: false }`
[INFO] [stdout] fb43dbdf7f32b227e2926d4b32ec2ac00c5c4a69fc63c8eaf90fedb804039f4a
[INFO] checking flexiber-0.1.1 against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] extracting crate flexiber 0.1.1 into /workspace/builds/worker-7-tc2/source
[INFO] validating manifest of crates.io crate flexiber 0.1.1 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 flexiber 0.1.1
[INFO] finished tweaking crates.io crate flexiber 0.1.1
[INFO] tweaked toml for crates.io crate flexiber 0.1.1 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 23 packages
[INFO] [stderr]       Adding hash32 v0.2.1 (latest: v0.3.1)
[INFO] [stderr]       Adding heapless v0.7.17 (latest: v0.8.0)
[INFO] [stderr]       Adding hex-literal v0.3.4 (latest: v0.4.1)
[INFO] [stderr]       Adding syn v1.0.109 (latest: v2.0.58)
[INFO] [stderr]       Adding synstructure v0.12.6 (latest: v0.13.1)
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] af8ecb2b67256172fcc3ef89e457bedc7c38314f6537be7915af9862bfaf5bb1
[INFO] running `Command { std: "docker" "start" "-a" "af8ecb2b67256172fcc3ef89e457bedc7c38314f6537be7915af9862bfaf5bb1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af8ecb2b67256172fcc3ef89e457bedc7c38314f6537be7915af9862bfaf5bb1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af8ecb2b67256172fcc3ef89e457bedc7c38314f6537be7915af9862bfaf5bb1", kill_on_drop: false }`
[INFO] [stdout] af8ecb2b67256172fcc3ef89e457bedc7c38314f6537be7915af9862bfaf5bb1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 9f90ffc7bc561ef47c9e72e8ef0d2e50d042234bde0816fa0eafd1627f911d45
[INFO] running `Command { std: "docker" "start" "-a" "9f90ffc7bc561ef47c9e72e8ef0d2e50d042234bde0816fa0eafd1627f911d45", kill_on_drop: false }`
[INFO] [stderr]    Compiling delog v0.1.7
[INFO] [stderr]    Compiling hex-literal v0.3.4
[INFO] [stderr]     Checking flexiber v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait `Taggable` is never used
[INFO] [stdout]    --> src/traits.rs:162:18
[INFO] [stdout]     |
[INFO] [stdout] 162 | pub(crate) trait Taggable<T: TagLike>: Sized {
[INFO] [stdout]     |                  ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `T3` is never constructed
[INFO] [stdout]    --> src/traits.rs:568:12
[INFO] [stdout]     |
[INFO] [stdout] 568 |     struct T3 {
[INFO] [stdout]     |            ^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` 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 1.76s
[INFO] running `Command { std: "docker" "inspect" "9f90ffc7bc561ef47c9e72e8ef0d2e50d042234bde0816fa0eafd1627f911d45", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9f90ffc7bc561ef47c9e72e8ef0d2e50d042234bde0816fa0eafd1627f911d45", kill_on_drop: false }`
[INFO] [stdout] 9f90ffc7bc561ef47c9e72e8ef0d2e50d042234bde0816fa0eafd1627f911d45