$ go mod init example.com/tstmod
Note that you need to include the v in the version tag.
$ go get github.com/pascal71/tstmod@v0.1.0
package main
import (
"fmt"
"github.com/pascal71/tstmod"
)
func main() {
fmt.Println(recursivefunc.Fac(3))
}
$ go test
$ git tag v0.1.0
$ git push origin --tags