check for existing VM now has different codepath for Windows and Linux

macos_okiomov.sh

@@ -97,7 +97,16 @@ fi
 
 # Finally done with dependencies.
 
-if [ -n "$(VBoxManage showvminfo "${vmname}")" ]; then
+
+if [ -z "${windows}" ]; then
+    if VBoxManage list vms | grep -q "${vmname}"; then
+        echo "${vmname} virtual machine already exists. Exiting."
+        exit
+elif [ -n "$(VBoxManage showvminfo "${vmname}")" ]; then
+    echo "${vmname} virtual machine already exists. Exiting."
+    exit
+fi
+
     echo "${vmname} virtual machine already exists. Exiting."
     exit
 fi