Blaise, 

This patch works for me. You may want to put additional checks in there, for example making sure that the path being added is not a directory. 

--Nick 

Index: gendeps
===================================================================
--- gendeps     (revision 31915)
+++ gendeps     (working copy)
@@ -73,6 +73,9 @@
     if not m in start_modules:
       try:
         file = inspect.getsourcefile(end_modules[m])
+        if not os.path.exists(file):
+          while not os.path.exists(file):
+            file = os.path.dirname(file)
         if type(file) == str:
           print >> stdout, file
       except Exception, e: