Recently I needed to find all duplicates of a file on some servers, but the duplicates might have a different file name. I was quite astounded that I could not find something that would do this. There are a lot of programs that will find all duplicates on a disk for you, but they will take forever, and I only needed to find duplicates of a single file. So I rolled my own. It is just a small perl script, but is quite fast nonetheless.
If you have a use case for something like this, you can get it from the Codeberg repo.