Special-casing G_FILE_ERROR_NOENT sounds like a good plan, but silencing the error altogether might be a step too far - it would be nice to get a hint if I accidentally mkdir `.../rules.e` instead of `.../rules.d`.
I've now added a commit to the PR so G_FILE_ERROR_NOENT is logged at LOG_LEVEL_INFO. Not sure if you want to close this bug, but I'm happy to reopen it if they'd prefer the tmpfiles.d route.
