When there is file called '1' or '2' in the root of MAUS distribution SCons issues the following error:

scons: Reading SConscript files ...
TypeError: File /opt/MAUS/devel/2 found where directory expected.:
File "/opt/MAUS/devel/SConstruct", line 494:
env.Tool('swig', '%s/third_party/swig-2.0.1' % maus_root_dir)
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Environment.py", line 1781:
toolpath = list(map(self._find_toolpath_dir, toolpath))
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Environment.py", line 1774:
return self.fs.Dir(self.subst(tp)).srcnode().abspath
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Node/FS.py", line 1347:
return self._lookup(name, directory, Dir, create)
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Node/FS.py", line 1314:
return root._lookup_abs(p, fsclass, create)
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Node/FS.py", line 2211:
result.diskcheck_match()
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Node/FS.py", line 1500:
"File %s found where directory expected.")
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Node/FS.py", line 384:
return self.func(*args, **kw)
File "/opt/MAUS/devel/third_party/install/lib/python2.7/site-packages/scons-2.1.0.alpha.20110323-py2.7.egg/scons-2.1.0.alpha.20110323/SCons/Node/FS.py", line 405:
raise TypeError(errorfmt % node.abspath)

Reproduce:
cd $MAUS_ROOT_DIR
touch 1 (or touch 2)
scons build