[INFO] fetching crate postfix 0.1.2...
[INFO] testing postfix-0.1.2 against master#caccb4d0368bd918ef6668af8e13834d07040417 for pr-146098-1
[INFO] extracting crate postfix 0.1.2 into /workspace/builds/worker-5-tc1/source
[INFO] started tweaking crates.io crate postfix 0.1.2
[INFO] finished tweaking crates.io crate postfix 0.1.2
[INFO] tweaked toml for crates.io crate postfix 0.1.2 written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate postfix 0.1.2 on toolchain caccb4d0368bd918ef6668af8e13834d07040417
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cac55698fca42dbba09102ff29c59764d82c5da2a93c7d9d8e4a1a709a228199
[INFO] running `Command { std: "docker" "start" "-a" "cac55698fca42dbba09102ff29c59764d82c5da2a93c7d9d8e4a1a709a228199", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cac55698fca42dbba09102ff29c59764d82c5da2a93c7d9d8e4a1a709a228199", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cac55698fca42dbba09102ff29c59764d82c5da2a93c7d9d8e4a1a709a228199", kill_on_drop: false }`
[INFO] [stdout] cac55698fca42dbba09102ff29c59764d82c5da2a93c7d9d8e4a1a709a228199
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a2bcd86607fdb4f89dd2af610fea655bf63da0f4ad9ee432f987cf72d91795bd
[INFO] running `Command { std: "docker" "start" "-a" "a2bcd86607fdb4f89dd2af610fea655bf63da0f4ad9ee432f987cf72d91795bd", kill_on_drop: false }`
[INFO] [stderr]    Compiling postfix v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/operator.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Unary(&'a Fn(f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Unary(&'a dyn Fn(f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/operator.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Binary(&'a Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Binary(&'a dyn Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/operator.rs:14:25
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn unary(f: &'a Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn unary(f: &'a dyn Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/operator.rs:18:26
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn binary(f: &'a Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn binary(f: &'a dyn Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `Command { std: "docker" "inspect" "a2bcd86607fdb4f89dd2af610fea655bf63da0f4ad9ee432f987cf72d91795bd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a2bcd86607fdb4f89dd2af610fea655bf63da0f4ad9ee432f987cf72d91795bd", kill_on_drop: false }`
[INFO] [stdout] a2bcd86607fdb4f89dd2af610fea655bf63da0f4ad9ee432f987cf72d91795bd
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 316ffccc0ddf0512467252715a95eae9c35861337576d3d1908dc0f756c4a5aa
[INFO] running `Command { std: "docker" "start" "-a" "316ffccc0ddf0512467252715a95eae9c35861337576d3d1908dc0f756c4a5aa", kill_on_drop: false }`
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/operator.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Unary(&'a Fn(f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Unary(&'a dyn Fn(f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling postfix v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/operator.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Binary(&'a Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Binary(&'a dyn Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/operator.rs:14:25
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn unary(f: &'a Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn unary(f: &'a dyn Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/operator.rs:18:26
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn binary(f: &'a Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn binary(f: &'a dyn Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/operator.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Unary(&'a Fn(f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 2 |     Unary(&'a dyn Fn(f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |               +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/operator.rs:3:16
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Binary(&'a Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Binary(&'a dyn Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/operator.rs:14:25
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn unary(f: &'a Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 14 |     pub fn unary(f: &'a dyn Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                         +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/operator.rs:18:26
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn binary(f: &'a Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     pub fn binary(f: &'a dyn Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stdout]    |                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "316ffccc0ddf0512467252715a95eae9c35861337576d3d1908dc0f756c4a5aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "316ffccc0ddf0512467252715a95eae9c35861337576d3d1908dc0f756c4a5aa", kill_on_drop: false }`
[INFO] [stdout] 316ffccc0ddf0512467252715a95eae9c35861337576d3d1908dc0f756c4a5aa
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 1b8b4667d45dbd1fff6fc88b24d58387547ee5ba866d7bcf450f1e90ed5a6698
[INFO] running `Command { std: "docker" "start" "-a" "1b8b4667d45dbd1fff6fc88b24d58387547ee5ba866d7bcf450f1e90ed5a6698", kill_on_drop: false }`
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]  --> src/operator.rs:2:15
[INFO] [stderr]   |
[INFO] [stderr] 2 |     Unary(&'a Fn(f64) -> Result<f64, &'static str>),
[INFO] [stderr]   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stderr]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]   |
[INFO] [stderr] 2 |     Unary(&'a dyn Fn(f64) -> Result<f64, &'static str>),
[INFO] [stderr]   |               +++
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]  --> src/operator.rs:3:16
[INFO] [stderr]   |
[INFO] [stderr] 3 |     Binary(&'a Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stderr]   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stderr]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]   |
[INFO] [stderr] 3 |     Binary(&'a dyn Fn(f64, f64) -> Result<f64, &'static str>),
[INFO] [stderr]   |                +++
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/operator.rs:14:25
[INFO] [stderr]    |
[INFO] [stderr] 14 |     pub fn unary(f: &'a Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stderr]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]    |
[INFO] [stderr] 14 |     pub fn unary(f: &'a dyn Fn(f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stderr]    |                         +++
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/operator.rs:18:26
[INFO] [stderr]    |
[INFO] [stderr] 18 |     pub fn binary(f: &'a Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]    |
[INFO] [stderr] 18 |     pub fn binary(f: &'a dyn Fn(f64, f64) -> Result<f64, &'static str>) -> Self {
[INFO] [stderr]    |                          +++
[INFO] [stderr] 
[INFO] [stderr] warning: `postfix` (lib) generated 4 warnings (run `cargo fix --lib -p postfix` to apply 4 suggestions)
[INFO] [stderr] warning: `postfix` (lib test) generated 4 warnings (4 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/postfix-3ac2c4a34df6827c)
[INFO] [stdout] 
[INFO] [stdout] running 8 tests
[INFO] [stdout] test tests::it_adds ... ok
[INFO] [stdout] test tests::it_divides_by_zero ... ok
[INFO] [stdout] test tests::it_divides ... ok
[INFO] [stdout] test tests::it_multiplies ... ok
[INFO] [stdout] test tests::it_adds_3 ... ok
[INFO] [stdout] test tests::it_respects_precedence ... ok
[INFO] [stdout] test tests::it_subtracts ... ok
[INFO] [stdout] test tests::it_uses_custom_operators ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 8 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests postfix
[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" "1b8b4667d45dbd1fff6fc88b24d58387547ee5ba866d7bcf450f1e90ed5a6698", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b8b4667d45dbd1fff6fc88b24d58387547ee5ba866d7bcf450f1e90ed5a6698", kill_on_drop: false }`
[INFO] [stdout] 1b8b4667d45dbd1fff6fc88b24d58387547ee5ba866d7bcf450f1e90ed5a6698