[INFO] fetching crate laboratory 2.0.0...
[INFO] checking laboratory-2.0.0 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate laboratory 2.0.0 into /workspace/builds/worker-5-tc1/source
[INFO] validating manifest of crates.io crate laboratory 2.0.0 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 laboratory 2.0.0
[INFO] finished tweaking crates.io crate laboratory 2.0.0
[INFO] tweaked toml for crates.io crate laboratory 2.0.0 written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate crates.io crate laboratory 2.0.0 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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded console v0.12.0
[INFO] [stderr]   Downloaded terminal_size v0.1.13
[INFO] [stderr]   Downloaded termios v0.3.2
[INFO] [stderr]   Downloaded syn v1.0.70
[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] bac5de782c8c8d01eb10a6de74bb2fe46c42fa07941130c92d7ab32efa12a580
[INFO] running `Command { std: "docker" "start" "-a" "bac5de782c8c8d01eb10a6de74bb2fe46c42fa07941130c92d7ab32efa12a580", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bac5de782c8c8d01eb10a6de74bb2fe46c42fa07941130c92d7ab32efa12a580", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bac5de782c8c8d01eb10a6de74bb2fe46c42fa07941130c92d7ab32efa12a580", kill_on_drop: false }`
[INFO] [stdout] bac5de782c8c8d01eb10a6de74bb2fe46c42fa07941130c92d7ab32efa12a580
[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] 4da4fbde279f6659a878a66b4a9baec713e777467a7f31ff3afbcde9ec9cbcd0
[INFO] running `Command { std: "docker" "start" "-a" "4da4fbde279f6659a878a66b4a9baec713e777467a7f31ff3afbcde9ec9cbcd0", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.70
[INFO] [stderr]    Compiling serde_derive v1.0.125
[INFO] [stderr]    Compiling serde v1.0.125
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking regex-syntax v0.6.18
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking convert_case v0.4.0
[INFO] [stderr]     Checking time v0.1.44
[INFO] [stderr]     Checking terminal_size v0.1.13
[INFO] [stderr]     Checking termios v0.3.2
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking regex v1.3.9
[INFO] [stderr]     Checking console v0.12.0
[INFO] [stderr]     Checking chrono v0.4.19
[INFO] [stderr]     Checking laboratory v2.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `PartialEq` is imported redundantly
[INFO] [stdout]  --> src/assertion.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::cmp::PartialEq;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `PartialEq` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `PartialEq` is imported redundantly
[INFO] [stdout]  --> src/assertion.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::cmp::PartialEq;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `PartialEq` 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: unused import: `std::rc::Rc`
[INFO] [stdout]  --> tests/tests.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::cell::RefCell`
[INFO] [stdout]  --> tests/tests.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::cell::RefCell;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `should_panic`
[INFO] [stdout]  --> tests/tests.rs:4:37
[INFO] [stdout]   |
[INFO] [stdout] 4 | use laboratory::{ describe, expect, should_panic, LabResult };
[INFO] [stdout]   |                                     ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `state`
[INFO] [stdout]   --> tests/tests.rs:15:27
[INFO] [stdout]    |
[INFO] [stdout] 15 |     ctx.before_each(move |state| {
[INFO] [stdout]    |                           ^^^^^ help: if this is intentional, prefix it with an underscore: `_state`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `state`
[INFO] [stdout]   --> tests/tests.rs:19:25
[INFO] [stdout]    |
[INFO] [stdout] 19 |     ctx.after_all(move |state| {
[INFO] [stdout]    |                         ^^^^^ help: if this is intentional, prefix it with an underscore: `_state`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spec`
[INFO] [stdout]   --> tests/tests.rs:24:25
[INFO] [stdout]    |
[INFO] [stdout] 24 |       suite.it("test", |spec| {
[INFO] [stdout]    |                         ^^^^ help: if this is intentional, prefix it with an underscore: `_spec`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 8.13s
[INFO] running `Command { std: "docker" "inspect" "4da4fbde279f6659a878a66b4a9baec713e777467a7f31ff3afbcde9ec9cbcd0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4da4fbde279f6659a878a66b4a9baec713e777467a7f31ff3afbcde9ec9cbcd0", kill_on_drop: false }`
[INFO] [stdout] 4da4fbde279f6659a878a66b4a9baec713e777467a7f31ff3afbcde9ec9cbcd0