Can't create Target on MacOS

Subprojects LLDB
1 
Hello,

I am trying to write lldb python script on MacOS. The script looks like: 

<b>import lldb

debugger = lldb.SBDebugger.Create()
debugger.SetAsync(False)
target = debugger.CreateTargetWithFileAndArch ("test", lldb.LLDB_ARCH_DEFAULT)
target.BreakpointCreateByLocation("test.c", 12)</b>

The script works on MacOS High Sierra 10.12.6. But on 10.13.6, "target" is None. Does anyone encounter similar problem or know what cause this problem?

Thanks,
Guolong