Rsync keeps copying the same file

I have used **rsync** for many years between linux filesystems without any problem with a very deterministic behavior. Now I try to use it on mac and experience some problem that some files (a small proportion of my 600000 files) gets copied over and over. Here is what I tried: 1. Moving from MacOS rsync 2.6.9 to rsync 3.1.3 (from brew) did not solve the problem. 2. Giving some large time interval in order to avoid possible clock skew did not resolve the problem. 3. I saw in some other answers that a possible problem is the *utf-8* vs *utf-8-mac* characters. I understand that it can be a problem but I am ready to accept ascii filenames for the purpose of having linux and mac coexisting. The files in question have ASCII file names. The weird think about it is that this unexpected behavior is completely deterministic. The same file **ListDebug/ForDEBUG** gets copied over and over. Yet the file **ListDebug/ForDEBUG2** which is next to it was not copied over and over. Any indication on the origin of this strange behavior would be much welcomed. EDIT: I found some more info when copying only the directory **ListDebug**. When I run **rsync -vadi -e ssh remote:ListDebug .** I get mathieu@MacBook-Pro: rsync -vadi -e ssh remote:ListDebug . >f.st......... ListDebug/ForDebug mathieu@MacBook-Pro: rsync -vadi -e ssh remote:ListDebug . >f.st......... ListDebug/ForDEBUG mathieu@MacBook-Pro: rsync -vadi -e ssh remote:ListDebug . >f.st......... ListDebug/ForDebug Thus there is some oscillation between one print and another. That really sounds strange and a bug. EDIT2: The file **ListDebug/ForDebug** gets copied but become named **ListDebug/ForDEBUG** and the file **ForDEBUG** never gets copied. EDIT3: If I change the content of ForDebug/ForDEBUG to something standard like TEST1, TEST2 then the bug remains. On the other hand if I rename the files ForDebug/ForDEBUG to file1/file2 then the bug disappear. Ve