Compacting to file(s) of size 0 bytes

In a backup summary email I noticed the following “compacting” messages. What concerns me are the “86 files with size of 0 bytes”.

Messages: [
Compacting because there are 223.58 MB in small volumes and the volume size is 50.00 MB,
Downloaded 51 file(s) with a total size of 223.58 MB, deleted 98 file(s) with a total size of 224.86 MB, and compacted to 86 file(s) with a size of 0 bytes, which reduced storage by 12 file(s) and 224.86 MB

Is that correct (ok), a bug in reporting (oops), a bug in compacting (uh, oh!), or something else?

It looks like a reporting issue (oops).

I just looked at the source, and it uses the on-disk temporary file to compute the value, which is wrong because it is not flushed. I am surprised that it is zero in your case, but I think I have fixed it now.