I have determined conclusively, through testing that took me close to a full day, that the API 28 compiler has severely restricted memory allocation. One of my app – granted a very complex one – will compile only if I disable 4000 of its 5800 processing blocks.
It seems that the memory was dropped by perhaps a factor of 3 from the previous compiler.
Moreover, the compilation failure is not accompanied by any error message that identify that inadequate memory allocation exist.
Please increase the compiler memory space back to the level the API 26 compiler had.