def listRedundantModules():
    """List modules that have been imported more than once via different paths."""
    mods = {}
    for name, mod in sys.modules.items():
        if not hasattr(mod, '__file__'):
            continue
        mfile = os.path.abspath(mod.__file__)
        if mfile[-1] == 'c':
            mfile = mfile[:-1]
        if mfile in mods:
            print("module at %s has 2 names: %s, %s" % (mfile, name, mods[mfile]))
        else:
            mods[mfile] = name