cmd/cgo: When building cgo, I get an error 'could not determine kind of name for var'

[rudyeeee]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.9.4 freebsd/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="freebsd"
GOOS="freebsd"
GOPATH="/root/work"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/freebsd_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -gno-record-gcc-switches"
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?

main.go ( https://play.golang.org/p/HrkbEQRd670 )

package main
  
/*
int test1() {

}
struct test2 {
        unsigned int ncpus;
        int epoch_number;
        int netmap_extra_bufs;
};

 */
import "C"

func main() {
        C.test1()
        var test C.test2
        _ = test
}

result:

go run main.go
./main.go:18:11: could not determine kind of name for C.test2

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

I want to build and run it correctly.

What did you see instead?

go run main.go
./main.go:18:11: could not determine kind of name for C.test2

[AlexRouSg]

https://golang.org/cmd/cgo/

To access a struct, union, or enum type directly, prefix it with struct_, union_, or enum_, as in C.struct_stat.

The type is named C.struct_test2

[rudyeeee]

It is my mistake. Thank you.