[INFO] fetching crate tagref 1.4.1...
[INFO] checking tagref-1.4.1 against master#836c31742687ba4e2f857b5b698e1e9e6b67619c for pr-81789
[INFO] extracting crate tagref 1.4.1 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate tagref 1.4.1 on toolchain 836c31742687ba4e2f857b5b698e1e9e6b67619c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tagref 1.4.1
[INFO] finished tweaking crates.io crate tagref 1.4.1
[INFO] tweaked toml for crates.io crate tagref 1.4.1 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate crates.io crate tagref 1.4.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a21c4b3a2e56ed05f6018f16bd71eedeca571fc89b3115bdbfb35fc4276e9f6e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "a21c4b3a2e56ed05f6018f16bd71eedeca571fc89b3115bdbfb35fc4276e9f6e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a21c4b3a2e56ed05f6018f16bd71eedeca571fc89b3115bdbfb35fc4276e9f6e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a21c4b3a2e56ed05f6018f16bd71eedeca571fc89b3115bdbfb35fc4276e9f6e", kill_on_drop: false }`
[INFO] [stdout] a21c4b3a2e56ed05f6018f16bd71eedeca571fc89b3115bdbfb35fc4276e9f6e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cd7f2a76671b70fa861459ba8d1f1e98755c4ad1b340599dc959bdc836c76ab6
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "cd7f2a76671b70fa861459ba8d1f1e98755c4ad1b340599dc959bdc836c76ab6", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking bstr v0.2.8
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking log v0.4.8
[INFO] [stderr]     Checking term_size v0.3.1
[INFO] [stderr]     Checking colored v1.9.0
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking globset v0.4.6
[INFO] [stderr]     Checking ignore v0.4.16
[INFO] [stderr]     Checking tagref v1.4.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> src/duplicates.rs:49:24
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 panic!(error);
[INFO] [stdout]    |                        ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_fmt_panic)]` on by default
[INFO] [stdout]    = note: this is no longer accepted in Rust 2021
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 panic!("{}", error);
[INFO] [stdout]    |                        ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 49 |                 std::panic::panic_any(error);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> src/duplicates.rs:80:24
[INFO] [stdout]    |
[INFO] [stdout] 80 |                 panic!(error);
[INFO] [stdout]    |                        ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this is no longer accepted in Rust 2021
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 80 |                 panic!("{}", error);
[INFO] [stdout]    |                        ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 80 |                 std::panic::panic_any(error);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> src/references.rs:38:20
[INFO] [stdout]    |
[INFO] [stdout] 38 |             panic!(error);
[INFO] [stdout]    |                    ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this is no longer accepted in Rust 2021
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 38 |             panic!("{}", error);
[INFO] [stdout]    |                    ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 38 |             std::panic::panic_any(error);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> src/references.rs:63:20
[INFO] [stdout]    |
[INFO] [stdout] 63 |             panic!(error);
[INFO] [stdout]    |                    ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this is no longer accepted in Rust 2021
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 63 |             panic!("{}", error);
[INFO] [stdout]    |                    ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 63 |             std::panic::panic_any(error);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 9.91s
[INFO] running `Command { std: "docker" "inspect" "cd7f2a76671b70fa861459ba8d1f1e98755c4ad1b340599dc959bdc836c76ab6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd7f2a76671b70fa861459ba8d1f1e98755c4ad1b340599dc959bdc836c76ab6", kill_on_drop: false }`
[INFO] [stdout] cd7f2a76671b70fa861459ba8d1f1e98755c4ad1b340599dc959bdc836c76ab6