fmt.Errorf might not be as bad as I thought

errors_test.go

package main

import (
	"errors"
	"fmt"
	"testing"
)

var err error

func BenchmarkErrorsNew(b *testing.B) {
	var e error
	for n := 0; n < b.N; n++ {
		e = errors.New("ruh roh")
	}

	err = e
}

func BenchmarkFmtErrorf(b *testing.B) {
	var e error
	for n := 0; n < b.N; n++ {
		e = fmt.Errorf("ruh roh")
	}

	err = e
}

errors_wrong_test.go

package main

import (
	"errors"
	"fmt"
	"testing"
)

func BenchmarkErrorsNew(b *testing.B) {
	for n := 0; n < b.N; n++ {
		_ = errors.New("ruh roh")
	}

}

func BenchmarkFmtErrorf(b *testing.B) {
	for n := 0; n < b.N; n++ {
		_ = fmt.Errorf("ruh roh")
	}
}

results.txt

 [fg-386] ~ > go test -bench=. -benchmem=true errors_test.go
goos: darwin
goarch: amd64
BenchmarkErrorsNew-8   	50000000	        24.6 ns/op	      16 B/op	       1 allocs/op
BenchmarkFmtErrorf-8   	20000000	        80.4 ns/op	      24 B/op	       2 allocs/op
PASS
ok  	command-line-arguments	2.982s
 [fg-386] ~ > go test -bench=. -benchmem=true errors_wrong_test.go
goos: darwin
goarch: amd64
BenchmarkErrorsNew-8   	2000000000	         0.29 ns/op	       0 B/op	       0 allocs/op
BenchmarkFmtErrorf-8   	20000000	        82.2 ns/op	      24 B/op	       2 allocs/op
PASS
ok  	command-line-arguments	2.369s