Change in 'cygstart' functionality?

Ken Brown
Tue Sep 13 17:53:00 GMT 2016

On 9/13/2016 10:50 AM, Nem W Schlecht wrote:
> Hello all,
> So, I used to be able to do this in Cygwin to open a chat session (in
> my case, With Skype for Business aka S4B):
>     cygstart ""
> But I noticed recently that this now fails with:
>     Unable to start 'sip': The specified file was not found.
> I have no idea why the colon ":" is getting converted into an a UTF
> F038 character.  I'm also unsure of when this stopped working, since I
> don't use it all that often.
> I thought maybe having some slashes would be required, so I tried:
>     cygstart "sip:/"
> Error:
>     Unable to start 'sip\': The specified file was not found.
> And yes, I did cut-paste that and *yes* the direction of the slash *changed*.
> With 2 slashes, a get an error in S4B that the address doesn't
> exist/is incorrect.
> With 3 slashes, a new chat window opens!  But its with user
> "///user@domain" (ie - non-existant user).
> Is the way the SIP protocol needs to be called broken or did something
> change in Cygwin to require slashes as a part of cygstart?

There's no code in cygstart to recognize the SIP protocol.  (It wouldn't 
be hard to add such code, as was done a few years ago for "mailto:". 
See line 598 of cygstart.c in the sources for the cygutils package.)

So cygstart treats "" as a file name.  The funny 
Unicode character you see comes from Cygwin's translation to allow ":" 
as part of a file name.  See


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