julia Cxx package different behavior when in module - c++

Question

I'm using Julia 1.1.1, and version 0.3.2 of Cxx. I'm finding that I'm getting an error when I call icxx"" from within a module I've defined, but not when I'm calling it in the REPL. In the REPL I have:
using Cxx
function xformVectors()
cxx"""
#include <iostream>
#include <vector>
class Summer {
public:
Summer() {}
std::vector<int> compute_sum(const std::vector<std::vector<int>> &input) {
std::vector<int> result(input.size(), 0);
for (std::size_t i = 0; i != input.size(); ++i) {
for (std::size_t j = 0; j != input[i].size(); ++j) {
result[i] += input[i][j];
}
}
return result;
}
};
"""
as = [rand(1:10,5), rand(1:10,6)]
x = convert(cxxt"std::vector< std::vector< int > >", as)
summer = #cxxnew Summer()
cxx_v = icxx"$summer->compute_sum($x);"
for v in cxx_v
println(collect(v))
end
end
If I then call xformVectors(), it writes out a couple of integers and exits (the expected behavior). If I use Pkg.generate() to wrap this code in a module, and then call xformVectors(), I get a fatal error:
ERROR: BoundsError: attempt to access 36-element Array{Tuple{AbstractString,Symbol,Int64,Int64,Bool},1} at index [37]
Stacktrace:
[1] getindex(::Array{Tuple{AbstractString,Symbol,Int64,Int64,Bool},1}, ::Int64) at ./array.jl:729
[2] #s37#70 at /home/jov9025/.julia/packages/Cxx/vxYtJ/src/cxxstr.jl:705 [inlined]
[3] #s37#70(::Any, ::Any, ::Any, ::Any) at ./none:0
[4] (::Core.GeneratedFunctionStub)(::Any, ::Vararg{Any,N} where N) at ./boot.jl:522
[5] xformVectors() at /home/jov9025/sandbox/julia/Vector2Vector.jl/src/Vector2Vector.jl:30
[6] top-level scope at none:0
If, in the REPL, I include the source file (include("src/Vector2Vector.jl") and then call Vector2Vector.xformVectors(), it runs without complaint.
Any idea what's going on?

Answer 1

The line in my code where the error originated was:
cxx_v = icxx"$summer->compute_sum($x);"
I still don't understand what the problem was with icxx"", but I don't actually need to use it in this sample (or in my real code). I can just use the #cxx macro, and voila, no crash:
cxx_v = #cxx compute_sum(x)
So, I may have been asking the wrong question (although I think it's an interesting one).
Revisiting this in January 2020: with version 0.3.3 of Cxx, the code executes fine with the original icxx"" line in the REPL.