$ python3 buildscripts/scons.py compiledb
...
scons: done reading SConscript files.
scons: Building targets ...
Building compilation database compile_commands.json
scons: done building targets.
TypeError: changed_since_last_build_node() takes 3 positional arguments but 4 were given:
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Script/Main.py", line 1374:
    _exec_main(parser, values)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Script/Main.py", line 1337:
    _main(parser)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Script/Main.py", line 1112:
    nodes = _build_targets(fs, options, targets, target_top)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Script/Main.py", line 1311:
    jobs.run(postfunc = jobs_postfunc)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Job.py", line 111:
    self.job.start()
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Job.py", line 410:
    task.executed()
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Script/Main.py", line 252:
    SCons.Taskmaster.OutOfDateTask.executed(self)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Taskmaster.py", line 317:
    t.release_target_info()
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Node/FS.py", line 3046:
    self.changed(allowcache=True)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Node/FS.py", line 3289:
    has_changed = SCons.Node.Node.changed(self, node)
  File "/home/mark/src/mongo/src/third_party/scons-3.1.1/scons-local-3.1.1/SCons/Node/__init__.py", line 1493:
    if _decider_map[child.changed_since_last_build](child, self, prev_ni, node):