stacktrace

scons: internal stack trace:
  File "/usr/local/lib/scons-3.0.1/SCons/Job.py", line 387, in start
    task.prepare()
  File "/usr/local/lib/scons-3.0.1/SCons/Script/Main.py", line 175, in prepare
    return SCons.Taskmaster.OutOfDateTask.prepare(self)
  File "/usr/local/lib/scons-3.0.1/SCons/Taskmaster.py", line 179, in prepare
    self.exception_raise()
  File "/usr/local/lib/scons-3.0.1/SCons/Taskmaster.py", line 554, in _exception_raise
    exec("raise exc_value.with_traceback(exc_traceback)")
  File "<string>", line 1, in <module>
  File "/usr/local/lib/scons-3.0.1/SCons/Taskmaster.py", line 828, in _find_next_ready_node
    children = executor.get_all_children()
  File "/usr/local/lib/scons-3.0.1/SCons/Executor.py", line 323, in get_all_children
    result.extend(target.children())
  File "/usr/local/lib/scons-3.0.1/SCons/Node/__init__.py", line 1370, in children
    self.scan()
  File "/usr/local/lib/scons-3.0.1/SCons/Node/__init__.py", line 1062, in scan
    executor.scan_sources(self.builder.source_scanner)
  File "/usr/local/lib/scons-3.0.1/SCons/Executor.py", line 486, in scan_sources
    self.scan(scanner, self.get_all_sources())
  File "/usr/local/lib/scons-3.0.1/SCons/Executor.py", line 503, in scan
    deps.extend(node.get_implicit_deps(env, scanner, path, kw))
  File "/usr/local/lib/scons-3.0.1/SCons/Node/__init__.py", line 957, in get_implicit_deps
    included_deps = [x for x in node.get_found_includes(env, scanner, path) if x not in seen]
  File "/usr/local/lib/scons-3.0.1/SCons/Node/FS.py", line 2883, in get_found_includes
    result = [n.disambiguate() for n in scanner(self, env, path)]
  File "/usr/local/lib/scons-3.0.1/SCons/Scanner/__init__.py", line 205, in __call__
    if self.scan_check and not self.scan_check(node, env):
  File "/usr/local/lib/scons-3.0.1/SCons/Scanner/__init__.py", line 311, in current_check
    return not node.has_builder() or node.is_up_to_date()
  File "/usr/local/lib/scons-3.0.1/SCons/Node/FS.py", line 3268, in is_up_to_date
    if not self.changed(r):
  File "/usr/local/lib/scons-3.0.1/SCons/Node/FS.py", line 3223, in changed
    has_changed = SCons.Node.Node.changed(self, node)
  File "/usr/local/lib/scons-3.0.1/SCons/Node/__init__.py", line 1459, in changed
    contents = self.get_executor().get_contents()
scons: building terminated because of errors.