Hello

I followed instruction from https://puredata.info/docs/faq/debian.

I added "deb http://apt.puredata.info/releases stable main" in /etc/apt/sources.list.

I used the stable keyword instead of testing because adding "deb http://apt.puredata.info/releases testing main" (as specified in https://puredata.info/docs/faq/debian) yields some errors. There is indeed no testing directory in http://apt.puredata.info/releases/dists/.

I then did both "sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key 9f0fe587374bbe81" and "sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key D63D3D09C39F5EEB".

When I do "sudo apt update", I get this error at the end:

[...]

Ign:3 http://apt.puredata.info/releases stable InRelease

[...]

Get:5 http://apt.puredata.info/releases stable Release [4870 B]
[...]
Get:7 http://apt.puredata.info/releases stable Release.gpg [904 B]
Ign:7 http://apt.puredata.info/releases stable Release.gpg

[...]

W: GPG error: http://apt.puredata.info/releases stable Release: The following signatures were invalid: EXPKEYSIG 9F0FE587374BBE81 Hans-Christoph Steiner <hans@guardianproject.info>
E: The repository 'http://apt.puredata.info/releases stable Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Is it a known problem?

Did I make a mistake somewhere?

Thank you for your time.

Best regards,

Johan Mazel