Your personal frustration and impatience is not an answer.
Even though a statement you made about macOS was technically correct, you did not explain exactly why.
First, I think context means everything. And as someone involved in this question/answer thread when it first came up, I was the first one to comment on the now deleted answer and wrote the following in my comment:
“My advice to you is be patient. You posted this question 3 hours ago and now you have given up. Wait for more answers and not engage with the question until a good solution is found.”
In the context of when it was closed and why it was closed, it was based on the fact that the original poster seemed to be frustrated and impatient. That’s it. And the “answer” provided no clear answer past “I guess this doesn’t work!”
Should that answer then be reopened? Nope.
The key points about efforts made should just be entered into the original question text. That “answer” was never an answer in any way.
Sorry to say this, but our original answer is still incorrect.
And this core claim in your deleted answer 100% incorrect:
“…it turns out that my answer that was deleted is indeed totally correct.”
No, your answer that was deleted was never correct.
You were frustrated, you gave up, and posted a venting of your frustration in the context of a non-answer posted within a mere 3 hours after you posted your question.
Then, pretty much a full 4 days later, an actual answer with actual details was posted that is very useful and very detailed.
While the your initial answer of the following is correct at a very high level:
“
rsynccannot be relied upon to operate correctly when sync'ing between anext4filesystem under linux and anAPFSfilesystem under MacOS.”
That still does not explain anything. This all has utterly nothing to do with ext4 and APFS being incompatible, but rather your Linux ext4 is case sensitive and the macOS APFS file system by default is case insensitive.
Technically if you wanted to you could reformat that macOS system to be APFS case sensitive. Or you could even plug in an external drive and format that as APFS case sensitive and make that external drive the Rsync destination.
Meaning, the core issue here is case sensitivity versus case insensitivity. This is not a “Linux versus macOS” issue where someone who rant about how “bad” macOS is and just rant and rave
macOS is not “bad” or “worse” than Linux. But by default what you want to do flies in the face of the default APFS case insensitivity that can easily be solved by either reformatting the disk as being case sensitive or adding an external drive formatted as being case sensitive.
That is why the accepted answer should stay the accepted answer. That answer is useful. The other answer you posted is, sadly, not an answer but frustration posted as an answer.