cmd/vet: possible to get a printf false positive with big.Int #30399
Description
What version of Go are you using (go version)?
$ go version go version go1.12 linux/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 GOARCH="amd64" GOBIN="" GOCACHE="/home/karalabe/.cache/go-build" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="linux" GOOS="linux" GOPATH="/tmp/go" GOPROXY="" GORACE="" GOROOT="/opt/google/go" GOTMPDIR="" GOTOOLDIR="/opt/google/go/pkg/tool/linux_amd64" GCCGO="gccgo" CC="gcc" CXX="g++" CGO_ENABLED="1" GOMOD="" 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-build576186895=/tmp/go-build -gno-record-gcc-switches"
What did you do?
Here's a full repro:
$ mkdir /tmp/go
$ GOPATH=/tmp/go
$ go get github.com/karalabe/govetrepro2/...
$ cd /tmp/go/src/github.com/karalabe/govetrepro2/
$ go test ./...
# github.com/karalabe/govetrepro2/bn256/google
bn256/google/main_test.go:16:3: Logf format %d has arg n of wrong type *math/big.Int
ok github.com/karalabe/govetrepro2/bn256/cloudflare 0.065s
FAIL github.com/karalabe/govetrepro2/bn256/google [build failed]
What did you expect to see?
The exact same test code (main_test.go) is present in both bn256/cloudflare and bn256/google. I expect either both to fail with the format error, or neither of them.
What did you see instead?
Cloudflare always passes, Google always fails.