Re: [Libguestfs] [PATCH nbdkit 1/5] vddk: Move minimum version to VDDK 6.0

It turns out that VDDK 6.0 async support is present but broken, which makes it hard to support this version. If it was missing we could use an alternative codepath, but present-and-broken is difficult to deal with. (There is no way to detect VDDK versions at run time.) Specifically it's a problem because the completion callback API changed between 6.0 and 6.5: < typedef void (*VixDiskLibCompletionCB)(void *cbData, uint64 sector, < VixError result); > typedef void (*VixDiskLibCompletionCB)(void *cbData, VixError result); Since the sector number parameter is usually != 0 and it masks the result parameter in the later API we think that every async call is returning an error. I think we would need to require VDDK 6.5 for this change. That was released in November 2016 (5 years ago) and updating VDDK is no big deal.