v1.12, embedding: unable to access globals in used module without updating world age

[Taaitaaiger]

The following code fails unless the commented line is enabled:

#include <julia.h>

JULIA_DEFINE_FAST_TLS

int main(int argc, char *argv[])
{
    jl_init();
    jl_value_t *dot = jl_get_global(jl_main_module, jl_symbol("dot"));
    assert(dot == NULL);

    jl_eval_string("using LinearAlgebra");
    
    // jl_current_task->world_age = jl_get_world_counter();
    dot = jl_get_global(jl_main_module, jl_symbol("dot"));
    assert(dot != NULL);

    jl_atexit_hook(0);

    return 0;
}

My understanding is that this fails because jl_eval_string calls jl_toplevel_eval_in, which reverts the update to the world age. jl_calling include has similar issues.

[vtjnash]

It looks like most (but not all) internal uses of jl_get_global may suffer from this same issue also