C:\cygwin64\bin\python3 doesn't work from cmd

[Thomas Wolff]

Am 07.10.2025 um 15:51 schrieb Aurélien Couderc via Cygwin:
> On Tue, Oct 7, 2025 at 3:47 PM Marco Atzeri via Cygwin
> <cygwin@cygwin.com> wrote:
>> On 07/10/2025 14:17, gamer 191 via Cygwin wrote:
>>> Hi,
>>> I noticed that C:\cygwin64\bin\python3 doesn't work if I invoke it from
>>> command prompt, likely because it doesn't have the .exe extension. It works
>>> if I create a copy named python3.exe.
>>> Kind regards,
>>> gamer191
>>>
>> Hi Gamer
>>
>> python3 is a Cygwin link managed by alternatives and NOT understood by
>> command prompt.
>>
>>
>> $ ls -l python3
>> lrwxrwxrwx 1 marco Administrators 25 May 21  2023 python3 ->
>> /etc/alternatives/python3
>>
>> $ alternatives --display python3
>> python3 - status is auto.
>>    link currently points to /usr/bin/python3.9
>> /usr/bin/python3.8 - priority 38
>> /usr/bin/python3.9 - priority 39
>> Current `best' version is /usr/bin/python3.9.
>>
>>   From CMD you need to invoke directly the relative python3.9.exe
>>
>> c:\cygwin64\bin>dir /A /S python3*.*
>>    Volume in drive C is OS
>>    Volume Serial Number is 2232-4AA9
>>
>>    Directory of c:\cygwin64\bin
>>
>> 21/05/2023  20:47                64 python3
>> 21/05/2023  20:48                78 python3-config
>> 10/03/2023  00:34             3,420 python3.8-config
>> 10/03/2023  00:34             9,747 python3.8.exe
>> 08/03/2023  23:52             3,048 python3.9-config
>> 08/03/2023  23:53             9,747 python3.9.exe
>>                  8 File(s)         38,879 bytes
> Could the setup.exe Cygwin installer PLEASE get a GUI(!!) option to
> install packages using native Windows symlinks? That would fix that
> recurring problem.
>
> Aurélien
It would also help, and not need such problematic reconfiguration, if ln 
-s did set up a symlink as .exe if it points to a .exe, like:
ln -s python3.9 /bin/pythonlink
ls -l /bin/pythonlink*
... /bin/pythonlink.exe -> python3.9.exe
Packages could also ensure this themselves with
ln -s python3.9.exe /bin/pythonlink.exe