[INFO] cloning repository https://github.com/johnsonw/graph_serialization
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/johnsonw/graph_serialization" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnsonw%2Fgraph_serialization", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnsonw%2Fgraph_serialization'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 66d100953c616d290cf630fb8747635fc6639b05
[INFO] checking johnsonw/graph_serialization against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnsonw%2Fgraph_serialization" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/johnsonw/graph_serialization 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 git repo https://github.com/johnsonw/graph_serialization
[INFO] finished tweaking git repo https://github.com/johnsonw/graph_serialization
[INFO] tweaked toml for git repo https://github.com/johnsonw/graph_serialization written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/johnsonw/graph_serialization 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] [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-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 58aa8df5884edefd79a7a06a3c2871f18c4403fca488d5609c1c7e63e5c6cb75
[INFO] running `Command { std: "docker" "start" "-a" "58aa8df5884edefd79a7a06a3c2871f18c4403fca488d5609c1c7e63e5c6cb75", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "58aa8df5884edefd79a7a06a3c2871f18c4403fca488d5609c1c7e63e5c6cb75", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "58aa8df5884edefd79a7a06a3c2871f18c4403fca488d5609c1c7e63e5c6cb75", kill_on_drop: false }`
[INFO] [stdout] 58aa8df5884edefd79a7a06a3c2871f18c4403fca488d5609c1c7e63e5c6cb75
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] bbd9f72fd5dcd98a1f2a685f187b97b279dcba53895ba1fbd39b73b9fdfa7185
[INFO] running `Command { std: "docker" "start" "-a" "bbd9f72fd5dcd98a1f2a685f187b97b279dcba53895ba1fbd39b73b9fdfa7185", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]    Compiling serde_derive v1.0.123
[INFO] [stderr]    Compiling serde v1.0.123
[INFO] [stderr]    Compiling indexmap v1.6.1
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking petgraph v0.5.1
[INFO] [stderr]     Checking test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `serde` is imported redundantly
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use serde; // 1.0.120
[INFO] [stdout]   |     ^^^^^ the item `serde` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json; // 1.0.61
[INFO] [stdout]   |     ^^^^^^^^^^ the item `serde_json` is already defined by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `petgraph` is imported redundantly
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use petgraph; // 0.5.1
[INFO] [stdout]   |     ^^^^^^^^ the item `petgraph` is already defined by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde` is imported redundantly
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use serde; // 1.0.120
[INFO] [stdout]   |     ^^^^^ the item `serde` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json; // 1.0.61
[INFO] [stdout]   |     ^^^^^^^^^^ the item `serde_json` is already defined by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `petgraph` is imported redundantly
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use petgraph; // 0.5.1
[INFO] [stdout]   |     ^^^^^^^^ the item `petgraph` is already defined by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 6.45s
[INFO] running `Command { std: "docker" "inspect" "bbd9f72fd5dcd98a1f2a685f187b97b279dcba53895ba1fbd39b73b9fdfa7185", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bbd9f72fd5dcd98a1f2a685f187b97b279dcba53895ba1fbd39b73b9fdfa7185", kill_on_drop: false }`
[INFO] [stdout] bbd9f72fd5dcd98a1f2a685f187b97b279dcba53895ba1fbd39b73b9fdfa7185
[INFO] checking johnsonw/graph_serialization against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjohnsonw%2Fgraph_serialization" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/johnsonw/graph_serialization 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 git repo https://github.com/johnsonw/graph_serialization
[INFO] finished tweaking git repo https://github.com/johnsonw/graph_serialization
[INFO] tweaked toml for git repo https://github.com/johnsonw/graph_serialization written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/johnsonw/graph_serialization 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-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 575d96d42dad7136157547acb9138288acd43cabc289be2abec6d52115942274
[INFO] running `Command { std: "docker" "start" "-a" "575d96d42dad7136157547acb9138288acd43cabc289be2abec6d52115942274", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "575d96d42dad7136157547acb9138288acd43cabc289be2abec6d52115942274", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "575d96d42dad7136157547acb9138288acd43cabc289be2abec6d52115942274", kill_on_drop: false }`
[INFO] [stdout] 575d96d42dad7136157547acb9138288acd43cabc289be2abec6d52115942274
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 59ff516b43c70387425c78ca26273b0a470c2a59311eeeb012b731b2f6a34ae8
[INFO] running `Command { std: "docker" "start" "-a" "59ff516b43c70387425c78ca26273b0a470c2a59311eeeb012b731b2f6a34ae8", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]    Compiling serde_derive v1.0.123
[INFO] [stderr]    Compiling serde v1.0.123
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]     Checking hashbrown v0.9.1
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling indexmap v1.6.1
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking petgraph v0.5.1
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/petgraph-0.5.1/src/graph_impl/stable_graph/serialization.rs:213:17
[INFO] [stdout]     |
[INFO] [stdout] 213 |                 Err(invalid_node_err(hole_pos.index(), node_bound))?;
[INFO] [stdout]     |                 ^^^ cannot infer type of the type parameter `T` declared on the enum `Result`
[INFO] [stdout]     |
[INFO] [stdout] help: consider specifying the generic arguments
[INFO] [stdout]     |
[INFO] [stdout] 213 |                 Err::<T, E2>(invalid_node_err(hole_pos.index(), node_bound))?;
[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] [stderr] error: could not compile `petgraph` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "59ff516b43c70387425c78ca26273b0a470c2a59311eeeb012b731b2f6a34ae8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59ff516b43c70387425c78ca26273b0a470c2a59311eeeb012b731b2f6a34ae8", kill_on_drop: false }`
[INFO] [stdout] 59ff516b43c70387425c78ca26273b0a470c2a59311eeeb012b731b2f6a34ae8