As others have mentioned, there’s sorting issues (are directory entries created in the same order for a project that compiled everything in a directory?), timestamps (archive files and many other formats embed timestamps), and things that you really want to be random (tmpdir on Linux [at least in the past] would create directories of varying length).
I’ve successfully built tools to compare Java JARs that required getting around two of those and other test tools that required the third. I’m sure there are more.
As others have mentioned, there’s sorting issues (are directory entries created in the same order for a project that compiled everything in a directory?), timestamps (archive files and many other formats embed timestamps), and things that you really want to be random (tmpdir on Linux [at least in the past] would create directories of varying length).
I’ve successfully built tools to compare Java JARs that required getting around two of those and other test tools that required the third. I’m sure there are more.