Thanks to this update: DST Root CA X3 Expiration (September 2021) DST Root CA X3 Expiration (September 2021) - Let's Encrypt wget and friends are broken on our Debian 9.x/10.x images on BeagleBoard.org - latest-images (10.3 2020-04-06 and earlier)…
root@beaglebone:~# wget https://rcn-ee.com/repos/debian/dists/buster/Release
--2021-10-20 14:17:49-- https://rcn-ee.com/repos/debian/dists/buster/Release
Resolving rcn-ee.com (rcn-ee.com)... 45.33.2.10, 2600:3c00::f03c:91ff:fe37:6ad5
Connecting to rcn-ee.com (rcn-ee.com)|45.33.2.10|:443... connected.
ERROR: The certificate of ‘rcn-ee.com’ is not trusted.
ERROR: The certificate of ‘rcn-ee.com’ has expired.
On a fresh install just run:
sudo apt update ; sudo apt install --only-upgrade libgnutls30
or make sure to keep your software up-to date:
sudo apt update ; sudo apt upgrade
Or use a newer Monthy Snapshot:
https://rcn-ee.net/rootfs/bb.org/testing/
Regards,