builder/vmware: verify various paths exist for Workstation

builder/vmware/driver_workstation9.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
@@ -104,6 +105,18 @@ func (d *Workstation9Driver) Verify() error {
 		}
 	}
 
+	if _, err := os.Stat(d.AppPath); err != nil {
+		return fmt.Errorf("VMware application not found: %s", d.AppPath)
+	}
+
+	if _, err := os.Stat(d.VmrunPath); err != nil {
+		return fmt.Errorf("'vmrun' application not found: %s", d.VmrunPath)
+	}
+
+	if _, err := os.Stat(d.VdiskManagerPath); err != nil {
+		return fmt.Errorf("'vmrun' application not found: %s", d.VdiskManagerPath)
+	}
+
 	// Check to see if it APPEARS to be licensed.
 	if err := workstationCheckLicense(); err != nil {
 		return err