SA5009: potential false-positive for byte arrays

[vcabbage]

staticcheck -version: build from master c702d0a
staticcheck -debug.version:

staticcheck (no version)

Compiled with Go version: go1.14
Main module:
        honnef.co/go/tools
Dependencies:
        github.com/BurntSushi/[email protected] (sum: h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=)
        golang.org/x/[email protected] (sum: h1:/iIZNFGxc/a7C3yWjGcnboV+Tkc7mxr+p6fDztwoxuM=)

go version: go version go1.14 linux/amd64
go env:

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/kale/.cache/go-build"
GOENV="/home/kale/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=[redacted]
GONOSUMDB=[redacted]
GOOS="linux"
GOPATH="/home/kale/go"
GOPRIVATE=[redacted]
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/kale/goroots/go1.14"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/kale/goroots/go1.14/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/kale/go/src/honnef.co/go/tools/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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build160255903=/tmp/go-build -gno-record-gcc-switches"

Command: staticcheck
Output:

main.go:8:13: Printf format %s has arg #1 of wrong type [4]byte (SA5009)

Playground: https://play.golang.org/p/aHfAniNvlEo

---

Using %s to format byte arrays isn't documented in the fmt package as far as I can tell. There is logic and tests for it though.

[dominikh]

Nice catch. Will fix.