[INFO] fetching crate panfix 0.4.0...
[INFO] checking panfix-0.4.0 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate panfix 0.4.0 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate panfix 0.4.0 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 panfix 0.4.0
[INFO] finished tweaking crates.io crate panfix 0.4.0
[INFO] tweaked toml for crates.io crate panfix 0.4.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate crates.io crate panfix 0.4.0 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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 7b5890ebbf5d4525b660ee9738d3cc4b8e96abb8ca1efa800f5679a5f72602dc
[INFO] running `Command { std: "docker" "start" "-a" "7b5890ebbf5d4525b660ee9738d3cc4b8e96abb8ca1efa800f5679a5f72602dc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7b5890ebbf5d4525b660ee9738d3cc4b8e96abb8ca1efa800f5679a5f72602dc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b5890ebbf5d4525b660ee9738d3cc4b8e96abb8ca1efa800f5679a5f72602dc", kill_on_drop: false }`
[INFO] [stdout] 7b5890ebbf5d4525b660ee9738d3cc4b8e96abb8ca1efa800f5679a5f72602dc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] f74ab8f87fc1ada8c03cd49d5f93fe3ece70003cd2ddadf97e52a1c76a3eabcb
[INFO] running `Command { std: "docker" "start" "-a" "f74ab8f87fc1ada8c03cd49d5f93fe3ece70003cd2ddadf97e52a1c76a3eabcb", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling syn v1.0.44
[INFO] [stderr]     Checking regex-syntax v0.6.18
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.13
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking regex v1.3.9
[INFO] [stderr]    Compiling thiserror-impl v1.0.21
[INFO] [stderr]     Checking thiserror v1.0.21
[INFO] [stderr]     Checking panfix v0.4.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/tree_visitor.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/tree_visitor.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> examples/json.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 24 |     String(String),
[INFO] [stdout]    |     ------ ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 24 |     String(()),
[INFO] [stdout]    |            ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> examples/json.rs:25:12
[INFO] [stdout]    |
[INFO] [stdout] 25 |     Number(f64),
[INFO] [stdout]    |     ------ ^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 25 |     Number(()),
[INFO] [stdout]    |            ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> examples/json.rs:26:13
[INFO] [stdout]    |
[INFO] [stdout] 26 |     Boolean(bool),
[INFO] [stdout]    |     ------- ^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 26 |     Boolean(()),
[INFO] [stdout]    |             ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> examples/json.rs:28:11
[INFO] [stdout]    |
[INFO] [stdout] 28 |     Array(Vec<Json>),
[INFO] [stdout]    |     ----- ^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 28 |     Array(()),
[INFO] [stdout]    |           ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> examples/json.rs:29:12
[INFO] [stdout]    |
[INFO] [stdout] 29 |     Object(HashMap<String, Json>),
[INFO] [stdout]    |     ------ ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 29 |     Object(()),
[INFO] [stdout]    |            ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 8.19s
[INFO] running `Command { std: "docker" "inspect" "f74ab8f87fc1ada8c03cd49d5f93fe3ece70003cd2ddadf97e52a1c76a3eabcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f74ab8f87fc1ada8c03cd49d5f93fe3ece70003cd2ddadf97e52a1c76a3eabcb", kill_on_drop: false }`
[INFO] [stdout] f74ab8f87fc1ada8c03cd49d5f93fe3ece70003cd2ddadf97e52a1c76a3eabcb