[Unison-hackers] [unison-svn] r285 - in trunk: . doc src src/lwt

[Benjamin Pierce]

Hi Jerome!

>> * Added some more debugging code to remote.ml to give more  
>> informative
>>   error messages when we encounter the (dreaded and longstanding)
>>   "assert failed during file transfer" bug
>
> I suspect this has something to do with the hack in function
> Copy.tryCopyMovedFile.  At least, someone synchronizing with
> a Windows machine reported that the assertion failure happened
> to him only when xferbycopying was set to true.  I suspect that
> some Windows ssh servers merges stderr and stdout.  As under
> Windows some information gets written on stderr when xferbycopying
> is true, the client receive a corrupted stream of data.
>
> Does this fit the other bug reports?

I've forgotten the details of the reports we've received about this,  
except for one more that also supports your hypothesis: This  
assertion failure seems to have appeared sometime after version 2.13.

Assuming this is really the problem, I guess the best fix is just to  
turn off these messages completely when some host is running  
Windows.  Users may be a little confused if they also sometimes use  
Unison to sync non-Windows boxes, but this seems minor.

Thanks for the help!!

     - Benjamin