error: cannot assign to type 'struct Foo' with type 'struct Foo'
|  --> in tests/fixtures/struct_compatibility.c:19:5
|
19   a = d;
|      ^
error: cannot assign to type 'union Bar' with type 'union Bar'
|  --> in tests/fixtures/struct_compatibility.c:27:6
|
27   u4 = u3;
|       ^
error: invalid binary expression: 'struct Foo *' '-' 'struct Foo *'
|  --> in tests/fixtures/struct_compatibility.c:31:18
|
31   int diff1 = &a - &z;
|                   ^
3 errors generated.