Calling function defined in another bundle does not work

I am trying to define a function in one bundle, and call it another, and i'm getting an error:

Heres an example that will reproduce the problem:

file argc_exit.uir:

.funcsig @exit_sig = (int<32>) -> ()
.funcdef @argc.exit <@exit_sig>
{
        %entry(<int<32>>%arg):
                CCALL #DEFAULT <ufuncptr<@exit_sig> @exit_sig> <ufuncptr<@exit_sig>>EXTERN "exit"(%arg)
                RET
}

file argc_inline.uir:

.typedef %char = int<8>
.funcdef @my_main <(int<32> uptr<uptr<%char>>)->(int<32>)> VERSION @my_main_v1
{
        %entry(<int<32>>%argc <uptr<uptr<%char>>>%argv):
                CALL <(int<32>)->()> @argc.exit (%argc)
                RET <int<32>>1
}

Then using my mu-tool-compiler: ./muc -r -f my_main argc_exit.uir argc_inline.uir emit/argc (use -c if you wan't to see the API calls it uses).

thread '<unnamed>' panicked at 'Operand 1013' is neither a local var or a global var', src/vm/api/api_impl/muirbuilder.rs:1290 stack backtrace: (the symbol with Id 1013 is @argc.exit).

I tracked the error down and it appears to be comming from the function get_treenode in (src\vm\api\api_impl\muirbuilder.rs). My guess is the API implementation only looks for things defined in the current bundle and not other bundles. However from my understanding of the Mu-spec you should be able to refer to entities declared in previously loaded bundles.

A workaround is to combine both files into the same bundle such as with ./muc -r -f my_main <(cat argc_exit.uir && cat argc_inline.uir) emit/argc.