.inprogress file

MacOS High Sierra

My Time Machine stopped backing up. It gave a message that the disk was full.

Research gave insight into getting rid of a file with a suffix of .inprogress.

I moved the .inprogress 0 byte file to the trash.

Time Machine is backing up as expected now.

The issue is that the 0 byte file is sitting happily in the trash, and will not delete no matter my attempts.

I really would love to get rid of that zombie 0 byte file.