Let's say I have a folder c:\test-ä in Windows

Now if I run: py -m venv env
and activate: env\scripts\activate
and check: where python

the result is incorrectly just: C:\Users\Username\AppData\Local\Programs\Python\Python36\python.exe

If I run: path 
the result is: PATH=C:\test-ä\env\Scripts;...

So clearly the encoding is broken for the folder name.

I can fix this by changing activate.bat character encoding to OEM-US and then replacing "test-├ż" by "test-ä".

If I now activate and run: where python
the result is (as should be): 
C:\test-ä\env\Scripts\python.exe
C:\Users\Username\AppData\Local\Programs\Python\Python36\python.exe

By running: path
I get: PATH=C:\test-ä\env\Scripts;...

So looks good here as well.

I suggest that what ever is creating activate.bat file, is using incorrect character encoding for the creation of the file. If this is somehow platform specific, there could be a guide in the venv documentation about how to fix this.