Hi George,
I’m on Arch, and initially I had installed it from the package here: https://www.archlinux.org/packages/community/x86_64/espeak-ng/ but then when I decided I wanted to try customising certain words, I went ahead with installing it from source.
It’s a while since I did it, but the instructions I followed were those written by Josh Meyer, here: http://jrmeyer.github.io/tts/2016/07/03/How-to-Add-a-Language-to-eSpeak-NG.html but with some reference to the repo itself. As I understand it, the repo has instructions based on what Josh had written up, so they’re pretty similar.
There’s someone else who posted a similar issue here: https://groups.io/g/espeak-ng/message/2637 and they also posted it in the discussion at the bottom of Josh’s instructions page mentioned above. Unfortunately they don’t list any resolution.
I see you also posted an issue in the repo. I doubt this will solve it but there are some useful pointers in this issue: https://github.com/espeak-ng/espeak-ng/issues/662 which may help rule things out.
Ultimately the problem looks like it’s connected to a change made to this file: https://github.com/espeak-ng/espeak-ng/blob/master/src/include/espeak-ng/espeak_ng.h
back in early 2019, whereby they added the symbol that’s complained about in the error message (espeak_ng_SetVoiceByFile):
As a short-term check I suppose you could try installing from the version of the source just prior to the commit where they added that symbol. That would give reassurance that it was that change at fault (or it would establish that it’s just a coincidence, but I doubt it, given the direct mention of the symbol name).
Kind regards,
Neil