* eval.c (copy_env, deep_copy_env): These functions are not following a protocol for object construction that is correct under generational GC. They are allocating a new object with make_obj first, and then calling functions to copy the constituent elements to populate into the object with a direct assignment. This direct assignment is wrong; the set macro is required. A better fix, rather than using the set macro, is to copy the constituent parts first, holding them in local variables, then allocate the new object, and finally, without doing any other memory allocating operations, assign the constituent parts into the new object.