libgnutls-version’s value is 30605
➜ bin ldd emacs-26.2 | grep gnutls
libgnutls.so.30 => /usr/lib/x86_64-linux-gnu/libgnutls.so.30 (0x00007f78d3a1e000)
I still suspect the issue may have been server rather than client. This system with the same configuration has been connecting to
elpa.gnu.org over https since I first built it when 26.2 was released. It is only today that I found https connections to
elpa.gnu.org failed.
Note also that to be sure, I did a rebuild and reinstall of emacs just in case it had been linked against an older library. This had no effect.
According the the gnutls NEWS file, this version does support 1.3
Tim