If you wish to report a defect or suggest an enhancement, please use the GNO Bugzilla.
Before you file a bug report, please ensure that it is actually a defect in GNO. The bug tracker is NOT a general support mechanism, such as if you're having problems trying to figure out how to do a particular task.
Second, having concluded that what you have is actually a bug (or enhancement request), please search bugzilla to ensure that it has not already been reported (or suggested). Note that there is more than one product supported by bugzilla.gno.org. Ensure that you are filing bugs under GNO itself and not one of the other products hosted by the GNO Consortium.
Be aware that the GNO Bugzilla uses self signed certificates. If you're getting warnings from your browser about the certificates, help is available (just note that the site name is for https://bugzilla.gno.org as opposed to https://lists.gno.org).
For an excellent article on submitting bug or defect reports in general (that is, for any software product), please see Simon Tatham's How to Report Bugs Effectively.
For GNO in particular, please ensure that for bug reports you're reporting at least the following information: