Been seeing these errors from def update for the past few nights:
Failed to synchronize cache for repo 'x2go-nightly-fedora' Failed to synchronize cache for repo 'x2go-extras-fedora' Ignoring repositories: x2go-nightly-fedora, x2go-extras-fedora
Turns out it was a bash issue. Older versions (for instance 4.3 as used on Ubunto 16.04 LTS) of bash don't support quotes in arithmetic expressions (or at least not very well), while newer versions (4.4 on Debian Stretch) don't seem to have any problem with that.
The newest, working certificate should valid from 06/02/2019 and have the SHA256/SHA1 fingerprints E4:48:B2:AD:8A:D1:D4:B7:35:D3:93:88:DE:93:C2:A1:0B:D2:24:93:3C:03:2F:6D:BA:23:9A:AC:14:89:21:A6 / 64:D4:B9:8F:04:0A:51:D8:DD:F6:15:2D:09:F0:ED:2F:9B:68:4F:4E.
That *doesn't* apply to wiki.x2go.org (and friends), which does have a different certificate.
Mihai