When I start the interpreter in Mint using the terminal, I get the debug output via standard output in the terminal window. Redirecting to a file also works without specifying the channel.
This answer may not help much now, but that seems to be the normal behavior.
Thank you for sharing. Okay that's strange. At least it seems that not I am doing something wrong but my Manjaro Linux is strange. I am done coding for today but next time I will try with other shells than bash. I recently even installed Powershell under Linux. Maybe on of them will behave as expected.