After the change to use realpath on loaded features, Solaris CI started failing in test_no_curdir (which tests behavior for running ruby without a working directory). I was able to trace the problem to the following call chain: rb_call_inits->Init_Thread->Init_thread_sync->rb_provide-> get_loaded_features_index->rb_check_realpath->rb_dir_getwd_ospath-> ruby_getcwd This will throw an exception, but because Ruby hasn't been fully initialized at the point the exception is thrown, it just exits with a status of 1. The bug here is that rb_check_realpath should not raise an exception, it should return nil. This bug is hit on Solaris because Solaris uses the realpath emulation instead of native realpath, and the realpath emualation raised instead of returning nil if the mode was RB_REALPATH_CHECK. Use rb_rescue in the realpath emulation if the mode is RB_REALPATH_CHECK, and swallow any exceptions raised and return nil.