Current progress. Perhaps I have hit a bug on Debian 9, hence the bonkers inducing behaviour. Using EDITOR has no effect. But if I set LYEDITOR to use gvim, it nearly works. This makes no sense to me.
Here's what I have for LYEDITOR, based on the NR:
export LYEDITOR='gvim --remote +:%(line)s:norm%(column)s % (file)s'
This invokes gvim, but with a hard to understand error
:if !exists('+acd')||!&acd|if haslocaldir()|cd -|lcd -|elseif getcwd() ==# '/hom
::1:norm3|cal foreground()|if &im|star|en|redr|f
[One has to admit that is slightly cryptic.]
Now I have never used gvim before today, so perhaps the servermorde has to be configured somehow?
Would anybody agree the ignoring of EDITOR is a bug?
Andrew