This hack re-adds the trailing slashes in the include path list for all asm tasks after they've been stripped.
Simply add the following code to the top level wscript:
import os
from waflib import TaskGen
@TaskGen.feature("asm")
@TaskGen.after_method("apply_incpaths")
def add_includes_paths(self):
self.env.INCPATHS = [os.path.join(x, "") for x in self.env.INCPATHS]