dynamic conpty loading

[Thomas Wolff]

Am 26.11.2025 um 11:32 schrieb Takashi Yano via Cygwin:
> On Fri, 21 Nov 2025 17:58:01 +0100
> Thomas Wolff wrote:
>
>> Am 21.11.2025 um 17:46 schrieb Corinna Vinschen via Cygwin:
>>> Hi Thomas,
>>>
>>> On Nov 21 16:46, Thomas Wolff via Cygwin wrote:
>>>> Am 21.11.2025 um 11:04 schrieb Takashi Yano via Cygwin:
>>>>> On Sun, 5 Oct 2025 10:15:55 +0200
>>>>> Thomas Wolff wrote:
>>>>>>>> The procedure seems to be:
>>>>>>>> try LoadLibrary("conpty.dll"), (if not successful, fallback to
>>>>>>>> GetModuleHandle("kernel32") instead) to retrieve GetProcAddress for
>>>>>>>> CreatePseudoConsole, ResizePseudoConsole, ClosePseudoConsole, and
>>>>>>>> then somehow (?) use those while calling CreateProcess.
>>>>>>>> The latter is woven into the cygwin library and I don't think it's a
>>>>>>>> good idea to clone that out of cygwin for a patched process creation
>>>>>>>> in mintty.
>>>>>>>>
>>>>>>>> My question/suggestion:
>>>>>>>> Can a cygwin mode switch to a selected conpty library instead of the
>>>>>>>> default one please?
>>> Where do you expect this conpty.dll to reside?
>>>
>>> If we do something like that, I would suggest to make sure that this
>>> conpty.dll is in a well-defined place. /bin or /lib might be a good
>>> idea. And if it exists in this defined place, it will be used by Cygwin.
>>>
>>> We can tweak the autoload mechanism to allow a primary DLL and a fallback
>>> DLL, that drops the need to set the CYWIN env var.
>>>
>>> The mintty package could contain a post-install script, or some other
>>> script in /bin to allow a user with admin rights downloading the latest
>>> (or the most sensible) conpty.dll from MSFT.
>>>
>>> Would that make sense?
>>>
>>>
>>> Corinna
>>>
>> That makes much sense, yes, thank you. /bin/conpty.dll would probably be
>> a good place.
> I checked the source of conpty.dll
> https://github.com/microsoft/terminal/blob/main/src/winconpty/winconpty.cpp
>
> conpty.dll seems to launch OpenConsole.exe in the directory where
> WindowsTerminal is installed.
> However, BUILTIN\Users does not have permission to execute OpenConsole.exe.
>
> Do you have some idea how to solve this problem?
> WindowsTerminal itself can launch OpenConsole.exe, so there should be
> some solutions, I think.
Did you install the nuget package? It can be extracted with zip, so you 
can install OpenConsole as a normal program...
I did not find a way, though, to invoke it explicitly so that it would 
solve the pty interworking problems.