[cygwin] Issue on output when using javac or scalac under emacs

[Eliot Moss]

On 8/26/2020 2:31 AM, Luc Henninger wrote:
> Le 26/08/2020 à 01:19, Jason Pyeron a écrit :
>>> -----Original Message-----
>>> From: Luc Henninger
>>> Sent: Tuesday, August 25, 2020 6:40 PM
>>>
>> I'm thick - what the issue? There was no body to the email.
>>
>>
> Hello,
> 
> ( My previous message dos not contain the text, only the attachments!!! )
> 
> For years, I use emacs-nt (the one provided by gnu.org) under cygwin. I just discover that emacs is 
> also directly provided by cygwin (late is better than never :-)). So I try to use it successfully up 
> to a compilation error in one of my program in java.
> 
> To compile java (or scala), I use my own makefile that I start from emacs.
> 
> In case of error, I encountered a strange output undex emacs_w32 and emacs_nox compared to emacs_nt 
> (see trace_nox, trace_w32 and trace_nt in attachment).
> 
> I currently use emacs release 27.1 for all emacses, but I verify that I have the same strange 
> behaviour with emacs 26.3.
> 
> Can anybody explain this? and more gane give a workaround?

Here's a thought.  Emacs NT would be a native Windows build of Emacs, so is definitely organized to 
interact properly with Windows subprocesses.  The Cygwin versions are designed to interact most 
easily with Cygwin subprocesses.  They can probably be made to work with Windows subprocesses, but 
as you found, there is at least one rough edge here.  My first guess would be something to do with 
line endings as they are conveyed back to the parent Emacs - the Windows "extra" CRs may confuse a 
Cygwin Emacs if it is not expecting them.  We sometimes see this with bash scripts brought over from 
Linux to Cygwin.  Anyway, this, or other character set related things, is where I would start to 
diagnose the issue and try different settings.  I would ask questions around what the terminal 
settings are that the subprocesses see, what exact characters are they outputting, etc.

Other are more expert than I in these details and may have specific settings to suggest that you 
look at :-) ...

Regards - Eliot Moss