[INFO] fetching crate kafi 0.1.2...
[INFO] testing kafi-0.1.2 against beta-2021-08-01 for beta-1.55-1
[INFO] extracting crate kafi 0.1.2 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate kafi 0.1.2 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate kafi 0.1.2
[INFO] finished tweaking crates.io crate kafi 0.1.2
[INFO] tweaked toml for crates.io crate kafi 0.1.2 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded bincode v0.9.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9f3151b30adce212749f5c99ff0b735df05449c159c4290572e96e0144e8fe31
[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" "9f3151b30adce212749f5c99ff0b735df05449c159c4290572e96e0144e8fe31", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9f3151b30adce212749f5c99ff0b735df05449c159c4290572e96e0144e8fe31", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9f3151b30adce212749f5c99ff0b735df05449c159c4290572e96e0144e8fe31", kill_on_drop: false }`
[INFO] [stdout] 9f3151b30adce212749f5c99ff0b735df05449c159c4290572e96e0144e8fe31
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f1560ae310c08f62b8fd6c186a0be00dab49e8452d95e06ebeae31f997e60321
[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" "f1560ae310c08f62b8fd6c186a0be00dab49e8452d95e06ebeae31f997e60321", kill_on_drop: false }`
[INFO] [stderr]    Compiling bincode v0.9.2
[INFO] [stderr]    Compiling kafi v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:45:32
[INFO] [stdout]    |
[INFO] [stdout] 45 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:51:32
[INFO] [stdout]    |
[INFO] [stdout] 51 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:56:57
[INFO] [stdout]    |
[INFO] [stdout] 56 |                 _data = deserialize(&buf).map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                                         ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/lib.rs:114:32
[INFO] [stdout]     |
[INFO] [stdout] 114 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]     |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/lib.rs:120:32
[INFO] [stdout]     |
[INFO] [stdout] 120 |                 .map_err(|e| e.description().to_string());
[INFO] [stdout]     |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]    --> src/lib.rs:148:24
[INFO] [stdout]     |
[INFO] [stdout] 148 |                   panic!(format!(
[INFO] [stdout]     |  ________________________^
[INFO] [stdout] 149 | |                     "Cannot flush {}: {:?}",
[INFO] [stdout] 150 | |                     self.file_path.display(),
[INFO] [stdout] 151 | |                     e
[INFO] [stdout] 152 | |                 ));
[INFO] [stdout]     | |_________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]     = note: the panic!() macro supports formatting, so there's no need for the format!() macro here
[INFO] [stdout] help: remove the `format!(..)` macro call
[INFO] [stdout]     |
[INFO] [stdout] 148 |                 panic!(
[INFO] [stdout] 149 |                     "Cannot flush {}: {:?}",
[INFO] [stdout] 150 |                     self.file_path.display(),
[INFO] [stdout] 151 |                     e
[INFO] [stdout] 152 |                 );
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.42s
[INFO] running `Command { std: "docker" "inspect" "f1560ae310c08f62b8fd6c186a0be00dab49e8452d95e06ebeae31f997e60321", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1560ae310c08f62b8fd6c186a0be00dab49e8452d95e06ebeae31f997e60321", kill_on_drop: false }`
[INFO] [stdout] f1560ae310c08f62b8fd6c186a0be00dab49e8452d95e06ebeae31f997e60321
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4db9d0b7a9462cd0edcbe93337442d978733f1098083c668f519f5cb3e28aec4
[INFO] running `Command { std: "docker" "start" "-a" "4db9d0b7a9462cd0edcbe93337442d978733f1098083c668f519f5cb3e28aec4", kill_on_drop: false }`
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:45:32
[INFO] [stdout]    |
[INFO] [stdout] 45 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:51:32
[INFO] [stdout]    |
[INFO] [stdout] 51 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:56:57
[INFO] [stdout]    |
[INFO] [stdout] 56 |                 _data = deserialize(&buf).map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                                         ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/lib.rs:114:32
[INFO] [stdout]     |
[INFO] [stdout] 114 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]     |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/lib.rs:120:32
[INFO] [stdout]     |
[INFO] [stdout] 120 |                 .map_err(|e| e.description().to_string());
[INFO] [stdout]     |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]    --> src/lib.rs:148:24
[INFO] [stdout]     |
[INFO] [stdout] 148 |                   panic!(format!(
[INFO] [stdout]     |  ________________________^
[INFO] [stdout] 149 | |                     "Cannot flush {}: {:?}",
[INFO] [stdout] 150 | |                     self.file_path.display(),
[INFO] [stdout] 151 | |                     e
[INFO] [stdout] 152 | |                 ));
[INFO] [stdout]     | |_________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]     = note: the panic!() macro supports formatting, so there's no need for the format!() macro here
[INFO] [stdout] help: remove the `format!(..)` macro call
[INFO] [stdout]     |
[INFO] [stdout] 148 |                 panic!(
[INFO] [stdout] 149 |                     "Cannot flush {}: {:?}",
[INFO] [stdout] 150 |                     self.file_path.display(),
[INFO] [stdout] 151 |                     e
[INFO] [stdout] 152 |                 );
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling kafi v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:45:32
[INFO] [stdout]    |
[INFO] [stdout] 45 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:51:32
[INFO] [stdout]    |
[INFO] [stdout] 51 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/lib.rs:56:57
[INFO] [stdout]    |
[INFO] [stdout] 56 |                 _data = deserialize(&buf).map_err(|e| e.description().to_string())?;
[INFO] [stdout]    |                                                         ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/lib.rs:114:32
[INFO] [stdout]     |
[INFO] [stdout] 114 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stdout]     |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/lib.rs:120:32
[INFO] [stdout]     |
[INFO] [stdout] 120 |                 .map_err(|e| e.description().to_string());
[INFO] [stdout]     |                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]    --> src/lib.rs:148:24
[INFO] [stdout]     |
[INFO] [stdout] 148 |                   panic!(format!(
[INFO] [stdout]     |  ________________________^
[INFO] [stdout] 149 | |                     "Cannot flush {}: {:?}",
[INFO] [stdout] 150 | |                     self.file_path.display(),
[INFO] [stdout] 151 | |                     e
[INFO] [stdout] 152 | |                 ));
[INFO] [stdout]     | |_________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]     = note: the panic!() macro supports formatting, so there's no need for the format!() macro here
[INFO] [stdout] help: remove the `format!(..)` macro call
[INFO] [stdout]     |
[INFO] [stdout] 148 |                 panic!(
[INFO] [stdout] 149 |                     "Cannot flush {}: {:?}",
[INFO] [stdout] 150 |                     self.file_path.display(),
[INFO] [stdout] 151 |                     e
[INFO] [stdout] 152 |                 );
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.55s
[INFO] running `Command { std: "docker" "inspect" "4db9d0b7a9462cd0edcbe93337442d978733f1098083c668f519f5cb3e28aec4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4db9d0b7a9462cd0edcbe93337442d978733f1098083c668f519f5cb3e28aec4", kill_on_drop: false }`
[INFO] [stdout] 4db9d0b7a9462cd0edcbe93337442d978733f1098083c668f519f5cb3e28aec4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 528b46f81598b6fabc93fd800a86f3cc804744ef4dd51bb1cc9e8ff5bbfa88f7
[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" "528b46f81598b6fabc93fd800a86f3cc804744ef4dd51bb1cc9e8ff5bbfa88f7", kill_on_drop: false }`
[INFO] [stdout] 
[INFO] [stderr] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout] running 7 tests
[INFO] [stderr]   --> src/lib.rs:45:32
[INFO] [stderr]    |
[INFO] [stderr] 45 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stderr]    |                                ^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(deprecated)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stderr]   --> src/lib.rs:51:32
[INFO] [stderr]    |
[INFO] [stderr] 51 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stderr]    |                                ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stderr]   --> src/lib.rs:56:57
[INFO] [stderr]    |
[INFO] [stderr] 56 |                 _data = deserialize(&buf).map_err(|e| e.description().to_string())?;
[INFO] [stderr]    |                                                         ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stderr]    --> src/lib.rs:114:32
[INFO] [stderr]     |
[INFO] [stderr] 114 |                 .map_err(|e| e.description().to_string())?;
[INFO] [stderr]     |                                ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stderr]    --> src/lib.rs:120:32
[INFO] [stderr]     |
[INFO] [stderr] 120 |                 .map_err(|e| e.description().to_string());
[INFO] [stderr]     |                                ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: panic message is not a string literal
[INFO] [stderr]    --> src/lib.rs:148:24
[INFO] [stderr]     |
[INFO] [stderr] 148 |                   panic!(format!(
[INFO] [stderr]     |  ________________________^
[INFO] [stderr] 149 | |                     "Cannot flush {}: {:?}",
[INFO] [stderr] 150 | |                     self.file_path.display(),
[INFO] [stderr] 151 | |                     e
[INFO] [stderr] 152 | |                 ));
[INFO] [stderr]     | |_________________^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stderr]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stderr]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stderr]     = note: the panic!() macro supports formatting, so there's no need for the format!() macro here
[INFO] [stderr] help: remove the `format!(..)` macro call
[INFO] [stderr]     |
[INFO] [stderr] 148 |                 panic!(
[INFO] [stderr] 149 |                     "Cannot flush {}: {:?}",
[INFO] [stderr] 150 |                     self.file_path.display(),
[INFO] [stderr] 151 |                     e
[INFO] [stderr] 152 |                 );
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: `kafi` (lib) generated 6 warnings
[INFO] [stderr] warning: `kafi` (lib test) generated 6 warnings (6 duplicates)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/kafi-3f80d5ef05e0c0d7)
[INFO] [stdout] test test::test_exists ... ok
[INFO] [stderr]    Doc-tests kafi
[INFO] [stdout] test test::test_remove ... ok
[INFO] [stdout] test test::test_another_inserts ... ok
[INFO] [stdout] test test::test_clear ... ok
[INFO] [stdout] test test::test_get ... ok
[INFO] [stdout] test test::test_already_filled ... ok
[INFO] [stdout] test test::test_auto_flush ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "528b46f81598b6fabc93fd800a86f3cc804744ef4dd51bb1cc9e8ff5bbfa88f7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "528b46f81598b6fabc93fd800a86f3cc804744ef4dd51bb1cc9e8ff5bbfa88f7", kill_on_drop: false }`
[INFO] [stdout] 528b46f81598b6fabc93fd800a86f3cc804744ef4dd51bb1cc9e8ff5bbfa88f7
