Thanks. Now at least I'm getting a different error. 
Now at Install pak I get the following error:
The downloaded binary packages are in
/var/folders/24/8k48jl6d249_n_qfxwsl6xvm0000gn/T//RtmpdZpwrt/downloaded_packages
Error: Error: <callr_remote_error: missing value where TRUE/FALSE needed>
in process 6431
-->
<async_rejected in if (any(bad <- types == "")) { stop("Can't parse remotes: ", paste(refs[bad], collapse = ", "))}: missing value where TRUE/FALSE needed>
If it helps, the log is here:
https://github.com/oharar/LatentINLA/runs/3534623088?check_suite_focus=true
The Github workflow is linked to above:
And the DESCRIPTION is here:
I'm sure the problem is due to me not knowing what I'm doing: there are too many moving parts that I don't understand.