<screen xmlns="http://www.scons.org/dbxsd/v1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.scons.org/dbxsd/v1.0 http://www.scons.org/dbxsd/v1.0/scons.xsd">% <userinput>scons -Q --debug=stacktrace</userinput>
scons: *** [prog.o] Source `prog.c' not found, needed by target `prog.o'.
scons: internal stack trace:
  File "SCons/Taskmaster/Job.py", line 219, in start
    task.prepare()
  File "SCons/Script/Main.py", line 180, in prepare
    return SCons.Taskmaster.OutOfDateTask.prepare(self)
  File "SCons/Taskmaster/__init__.py", line 195, in prepare
    executor.prepare()
  File "SCons/Executor.py", line 418, in prepare
    raise SCons.Errors.StopError(msg % (s, self.batches[0].targets[0]))
</screen>
