Whenever we have changed the file format version, there are inevitably lots of other issues that are attributed to VDB as a result of this warning:

Warning: unsupported VDB file format (expected version 223 got version 224)

The reason for the warning is clear - if there is a feature in use that cannot be used with an earlier reader, the reading will fail. However, we don't know when we write this version number into the file that this feature is even in use, so it could be ignored.

This makes me very reticent to ever consider changing the file format.

Think we should discuss what to do here. We can reword this warning to make it a little more explicit what it means. Although we would still need to wait for all existing software to upgrade their readers to pick up this change before we could change the file format version without as much backlash.

We could perhaps also detect if a file will be written with any features that are later file format features and if not write the file with the earlier version number? There's no existing mechanism to achieve this though.

Looking for ideas on how to go about solving this.