Bug report: diff

Wed Jun 25 20:50:13 GMT 2025

On 6/25/2025 4:28 PM, Eliot Moss via Cygwin wrote:
> On 6/25/2025 3:03 PM, Brian Inglis via Cygwin wrote:
>> On 2025年06月24日 19:46, Eliot Moss via Cygwin wrote:
>>> The following used to work, but now does not:
>>> diff -q --to-file=old foo.tex bar.tex
>>> where old is a sub-directory of the current directory.
>>> This always reports:
>>> diff: old: No such file or directory
>>> It's ok when only one file is listed:
>>> diff -q --to-file=old foo.tex
>>>> Do you have entries ./old/{foo,bar}.tex, do each differ from respective
>> ./{foo,bar}.tex, and are there any other entries or directories under ./old/?
>> I tried with and without.  It complains (obviously :-) ) if one of the .tex files
> does not actually exist, but that's distinct from complaining about old, which *does*
> exist.
>>> Are there are any file name case differences or symlinks in paths?
>> No case differences, no symlinks.
>>> It is often more useful to ls -l (-gG) and diff (-q) actual directories
>> ./{,old/} so we can see all relevant information (maybe sanitize info if necessary).
>> ls -lG old ==>
> -rwxrw----+ 1 moss 13811 Jun 24 19:02 arch.tex
> -rwxrw----+ 1 moss 35714 Jun 24 19:02 background.tex
> -rwxrw----+ 1 moss  6847 Jun 24 19:02 intro.tex
> -rwxrw----+ 1 moss  9124 Jun 24 19:03 progress.tex
> -rwxrw----+ 1 moss 15858 Jun 23 22:31 proposal.bib
> -rwxrw----+ 1 moss 13703 Jun 24 19:03 proposal.tex
> -rwxrw----+ 1 moss 12836 Jun 24 19:02 proposed.tex
> -rwxrw----+ 1 moss  6541 Jun 24 19:02 timeline.tex
>> ls -lG ./*.tex ==>
> -rwxrw----+ 1 moss 13811 Jun 24 19:02 ./arch.tex
> -rwxrw----+ 1 moss 35714 Jun 24 19:02 ./background.tex
> -rwxrw----+ 1 moss  6847 Jun 24 19:02 ./intro.tex
> -rwxrw----+ 1 moss  9124 Jun 24 19:03 ./progress.tex
> -rwxrw----+ 1 moss 13703 Jun 24 19:03 ./proposal.tex
> -rwxrw----+ 1 moss 12836 Jun 24 19:02 ./proposed.tex
> -rwxrw----+ 1 moss  6541 Jun 24 19:02 ./timeline.tex
>> ls -lGd . old ==>
> drwxrwx---+ 1 moss 0 Jun 24 21:32 .
> drwxrwx---+ 1 moss 0 Jun 24 21:32 old
>>> Any reason why you chose --to-file option for your old directory rather than the more conventional --from-file option?
>> Not really.  --from-file gives the same error.  Near as I can tell it is always failing
> when --to-file/--from-file is a directory and there is a list of more than one file.
>>> If you could check whether the issue appeared in 3.11 and worked okay in 3.10 or point to the failing version that 
>> would be useful.
>> Ok, I'll try older versions of the diff package and try to narrow when the behavior changed.

The answer is:
3.11-1 exhibits the undesired behavior
3.10-1 does not
So I guess it's something in those ~250 commits (sorry!).
Regards - Eliot Moss