How to fix "unable to create pristine install stream"

Since about one or two weeks I get this error message and I don't know how to resolve it.

Commit failed (details follow):

Unable to create pristine install stream

The system cannot find the path specified.

I neither know what a Pristine Install Stream is, nor does the message contain a hint about the path that is not found.

I've tried a cleanup, but the same error still occurs.

I googled, but at the time of writing there are only 9 results available, some of them commit history of SVN changes, others unanswered question.

I dug into it with Process Monitor and I found a line (one column per line below)

21:06:17,6337584    
TortoiseProc.exe    
14144   
CreateFile  
[...]\.svn\tmp\svn-4F235F40 
PATH NOT FOUND  
Desired Access: Generic Write, Read Attributes, Delete, 
Disposition: Create, 
Options: Synchronous IO Non-Alert, Non-Directory File, 
Attributes: N, 
ShareMode: None, 
AllocationSize: 0

Looking at my hard disk, I saw that there's no tmp folder inside my .svn folder.

Creating the tmp folder manually resolved the issue.

On my system, the tmp folder was in the .svn directory. So I did rm -rf tmp in the .svn directory. Then mkdir tmp in the .svn directory and it fixed the problem.