cmd/go: coverpkg=all fails when dot imports . are present #23432
Description
What version of Go are you using (go version)?
go1.10beta2
go version devel +594668a5a9 Thu Jan 11 17:44:08 2018 +0000 darwin/amd64
Does this issue reproduce with the latest release?
With go1.9.2 it works fine:
$ go test -coverpkg=all ./...
warning: no packages being tested depend on archive/tar
...
warning: no packages being tested depend on vendor/golang_org/x/text/unicode/norm
? demo [no test files]
What operating system and processor architecture are you using (go env)?
$ go env
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/myself/go/demo"
GORACE=""
GOROOT="/Users/myself/.gvm/gos/go1.9.2"
GOTOOLDIR="/Users/myself/.gvm/gos/go1.9.2/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/1_/931p_3ms15b07mhkkmmzz1qc0000gp/T/go-build361849763=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
What did you do?
Created main.go:
package main
import . "fmt"
func main() {
Println("example")
}
Ran test with -coverpkg=all
$ go test -coverpkg=all ./...
# demo
./main.go:5: invalid array index 0 (out of bounds for 0-element array)
./main.go:9: GoCover_0 redeclared in this block
previous declaration during import "fmt"
What did you expect to see?
Should have no errors, same as when -coverpkg=all is not specified:
$ go test ./...
? demo [no test files]
What did you see instead?
-coverpkg=all seems to be adding variables GoCover_0 to the current package as well as the . imported "fmt" package. That causes the current package to not compile because GoCover_0 is redeclared in this package.