I created an issue at JuliaCall however after a first inspection, I think it is actually an RCall issue.

Concretely something in the following is not raising julia errors when run on R. Also the stacktrace is not reported.

Helpful steps to provide error support

Looking into JuliaCall's error handling, there are two places:

1. on JuliaCall julia side the following try catch converts a julia error to an R object https://github.com/Non-Contradiction/JuliaCall/blob/c05473bea78a0197c639f7e82ab1c6f2e943e1cc/inst/julia/setup.jl#L165-L194

function docall(call1)
    try
        # ...
    catch e
        Rerror(e, stacktrace(catch_backtrace())).p;
    end;
end

2. on JuliaCall R side the following intercepts these R objects and raises them as R errors https://github.com/Non-Contradiction/JuliaCall/blob/c05473bea78a0197c639f7e82ab1c6f2e943e1cc/R/interface.R#L76-L78

    r <- .julia$do.call_(jcall)

    if (inherits(r, "error")) stop(r)

Both these steps would need to be replicated inside the conversion of a Julia Function to an R function.