testing: benchmark example shows vet warning #37341
Description
What version of Go are you using (go version)?
$ go version go version go1.13.4 darwin/amd64
Does this issue reproduce with the latest release?
Yes.
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/Users/masahiro.furudate/Library/Caches/go-build" GOENV="/Users/masahiro.furudate/Library/Application Support/go/env" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GONOPROXY="" GONOSUMDB="" GOOS="darwin" GOPATH="/Users/masahiro.furudate/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/Cellar/go/1.13.4/libexec" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/Cellar/go/1.13.4/libexec/pkg/tool/darwin_amd64" GCCGO="gccgo" AR="ar" CC="clang" CXX="clang++" CGO_ENABLED="1" GOMOD="/Users/masahiro.furudate/work/go/go/src/go.mod" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/wp/wd7n1rkd5ln8v4c3qsw891vnkvjmym/T/go-build202688006=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
I ran go vet on the very first Benchmarks example.
https://golang.org/pkg/testing/#hdr-Benchmarks
What did you expect to see?
No warning.
What did you see instead?
I saw the warning "result of fmt.Sprintf call not used".