correct the picking of build log in tests

tests.py

@@ -294,7 +294,7 @@ def test_install_environment_zlib():
     )
     assert len(build_log) == 2
     # take the most recent build log
-    build_log = sorted(build_log)[0]
+    build_log = sorted(build_log)[1]
     # check that the build log contains statement ##### Installation finished
     with open(build_log, "r") as f:
         lines = f.read()