# D001 int_overflow

URL: /docs/errors/D001
Markdown: /docs/errors/D001.md

> Checked Int arithmetic overflowed 64 bits.

A runtime defect: the running program stops with it; no compile phase reports it, and `try` cannot catch it. `sakura explain D001` prints this explanation offline.

Checked `Int` arithmetic overflowed 64 bits. Defects are bugs, not errors: they are not in the
effect row and cannot be caught by `try`.

Runtime defects come from running programs, so `compiler/tests/ui` has no fixture for them; the explanation above names the repair.