tweak

tests/test_io.py

@@ -132,7 +132,7 @@ class TestFitsHeaderOps(unittest.TestCase):
 
     def test_get_proc_info(self):
         proc_info = get_proc_info()
-        self.assertEquals(proc_info["BUILD"], "__unset__")
+        self.assertEquals(proc_info["BUILD"], "")
 
     def test_generate_meta(self):
         h = generate_meta()