Build of 7.8.866 getting stuck in a loop

PEEP at 468: nop => PEEP at 468: nop => PEEP at 470: mark global(2) => mark & global(2) PEEP at 471: assign local and pop(1) local(1) => assign local(1) PEEP at 471: push int(0) => push 0 PEEP at 471: push 0 index => int index(0) PEEP at 472: mark local(1) => mark & local(1) PEEP at 473: mark call builtin(23) => mark, call builtin(23) PEEP at 474: push 0 assign local and pop(5) => clear local(5) PEEP at 474: clear local(5) & local(5) => & local(5) clear local(5) PEEP at 475: local(5) clear string subtype index => local index(5) PEEP at 475: global(3) local index(5) => global[local](3,5) PEEP at 476: mark global(3) => mark & global(3) PEEP at 476: local(5) clear string subtype index => local index(5) PEEP at 477: mark local(5) => mark & local(5) PEEP at 477: local(5) clear string subtype index => local index(5) PEEP at 477: global(3) local index(5) => global[local](3,5) PEEP at 474: nop => PEEP at 474: nop => PEEP at 479: call builtin 1(24) pop => call builtin1 & pop(24) PEEP at 480: push 0 assign local and pop(5) => clear local(5) PEEP at 480: clear local(5) & local(5) => & local(5) clear local(5) PEEP at 481: mark local(5) => mark & local(5) PEEP at 481: local(3) local(5) => 2 locals(3,5) PEEP at 481: 2 locals(3,5) clear string subtype index => local[local](5,3) PEEP at 482: push int(0) => push 0 PEEP at 482: push 0 index => int index(0) PEEP at 483: local(4) local(5) => 2 locals(4,5) PEEP at 483: push int(1) => push 1 PEEP at 483: push 1 index => int index(1) PEEP at 480: nop => PEEP at 480: nop => PEEP at 487: push 0 assign local and pop(5) => clear local(5) PEEP at 487: clear local(5) & local(5) => & local(5) clear local(5) PEEP at 488: mark string(147) => mark & string(147) PEEP at 489: local(4) local(5) => 2 locals(4,5) PEEP at 489: 2 locals(4,5) clear string subtype index => local[local](5,4) PEEP at 487: nop => PEEP at 487: nop => PEEP at 490: push 0 assign local and pop(5) => clear local(5) PEEP at 490: clear local(5) & local(5) => & local(5) clear local(5) PEEP at 491: local(5) clear string subtype index => local index(5) PEEP at 491: global(5) local index(5) => global[local](5,5) PEEP at 492: assign local and pop(6) local(6) => assign local(6) PEEP at 492: push int(-2147483648) => push -int(-2147483648) PEEP at 492: push -int(-2147483648) => push int(-2147483648) PEEP at 492: push int(-2147483648) => push -int(-2147483648) PEEP at 492: push -int(-2147483648) => push int(-2147483648) ... ad infinitum.

So an integer overflow, but why?