To whom it may concern...

On a new machine with openSuSE Leap 15.3 i did (as root and according to https://wiki.trinitydesktop.org/OpenSUSE_Trinity_Repository_Installation_Instructions)

rpm --import http://mirror.ppa.trinitydesktop.org/trinity/rpm/opensuse15.3/RPM-GPG-KEY-trinity
zypper ar http://mirror.ppa.trinitydesktop.org/trinity/rpm/opensuse15.3/trinity-r14/RPMS/x86_64 trinity
zypper ar http://mirror.ppa.trinitydesktop.org/trinity/rpm/opensuse15.3/trinity-r14/RPMS/noarch trinity-noarch

without a problem. But the next command

zypper refresh

produced this:

Retrieving repository 'trinity' metadata ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------[\]
Signature verification failed for file 'repomd.xml' from repository 'trinity'.

    Note: Signing data enables the recipient to verify that no modifications occurred after the data
    were signed. Accepting data with no, wrong or unknown signature can lead to a corrupted system
    and in extreme cases even to a system compromise.

    Note: File 'repomd.xml' is the repositories master index file. It ensures the integrity of the
    whole repo.

    Warning: This file was modified after it has been signed. This may have been a malicious change,
    so it might not be trustworthy anymore! You should not continue unless you know it's safe.

Signature verification failed for file 'repomd.xml' from repository 'trinity'. Continue? [yes/no] (no): no
Retrieving repository 'trinity' metadata ............................................................................................................................................................................................[error]
Repository 'trinity' is invalid.
[trinity|http://mirror.ppa.trinitydesktop.org/trinity/rpm/opensuse15.3/trinity-r14/RPMS/x86_64] Valid metadata not found at specified URL
History:
- Signature verification failed for repomd.xml
- Can't provide /repodata/repomd.xml

Please check if the URIs defined for this repository are pointing to a valid repository.
Skipping repository 'trinity' because of the above error.
Retrieving repository 'trinity-noarch' metadata .....................................................................................................................................................................................[error]
Repository 'trinity-noarch' is invalid.
[trinity-noarch|http://mirror.ppa.trinitydesktop.org/trinity/rpm/opensuse15.3/trinity-r14/RPMS/noarch] Valid metadata not found at specified URL
History:
- File './repodata/df43098b8eb4b9b9c38b0bdd574746245eefd9ee3a6677672736a3db059791b9-primary.xml.gz' not found on medium 'http://mirror.ppa.trinitydesktop.org/trinity/rpm/opensuse15.3/trinity-r14/RPMS/noarch'
- Can't provide ./repodata/df43098b8eb4b9b9c38b0bdd574746245eefd9ee3a6677672736a3db059791b9-primary.xml.gz

Please check if the URIs defined for this repository are pointing to a valid repository.
Skipping repository 'trinity-noarch' because of the above error.
Some of the repositories have not been refreshed because of an error.

The mirrors on

https://ftp.fau.de/trinity/trinity/rpm/opensuse15.3/trinity-r14/RPMS/x86_64
http://mirror.nasutek.com/trinity/trinity/rpm/opensuse15.3/trinity-r14/RPMS/x86_64/
http://tde-mirror.yosemite.net/trinity/rpm/opensuse15.3/trinity-r14/RPMS/x86_64/

are showing the same problem.

Peter