Hi Troels, In running the test suite, I noticed the following test failing: $ ./relax --verification-tests Library.test_library_independence The problem is the lib.system module, in that you cannot import the status module. Instead you should call status.observers.system_cwd_path.notify() after any calls to lib.system.cd(), i.e. outside of the relax library, rather than in this function itself. Cheers, Edward