PTY not working in Mintty

Marco Atzeri
Fri Apr 10 12:24:22 GMT 2020

Am 10.04.2020 um 14:05 schrieb Pavel Fedin via Cygwin:
>    Hello everyone!
>    I have two machines in my posession: a desktop and a laptop. Both
> machines have Windows 10 and the same up to date version of Cygwin
> installed. The only difference is "age". The laptop is a new one, with
> freshly installed OS and Cygwin, and the desktop is about one year old
> and its hard drive is about 10 years old, Cygwin was installed a while
> ago and periodically upgraded.
>    So far, on the desktop PTY does not work. Attempt to run docker (i am
> using Docker Desktop for Windows) causes "Terminal is not a PTY" error,
> i have to use winpty wrapper as suggested. On the laptop everything is
> fine, docker works in MinTTY out of the box with no need for winpty.
>    Is there maybe some hidden setting, which got stuck somewhere in the
> older system ? Why is PTY not working? Can anyone help me to diagnose that ?

Hi pavel,

what is the setting of CYGWIN variable ?

I suggest you to run

"cygcheck -svr > cygcheck.out" and compare the output files

No idea what is "Docker Desktop" but I suggest you to verify that you 
are really running mintty with the same invocation in the two cases.


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