# D091 host_failure

URL: /docs/errors/D091
Markdown: /docs/errors/D091.md

> A host operation failed outside Sakura Lang's control (for example a rejected host promise).

A runtime defect: the running program stops with it; no compile phase reports it, and `try` cannot catch it. `sakura explain D091` prints this explanation offline.

A host operation failed outside Sakura Lang's control (for example a rejected host promise).
The defect carries the host's message; check the host environment (the Node version, file
permissions, the network) and report it if the program and host look correct.

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