Auto merge of #72089 - Mark-Simulacrum:error-is-really-an-error, r=pietroalbini
Auto merge of #72089 - Mark-Simulacrum:error-is-really-an-error, r=pietroalbini

Fail if I/O error occurs during testing

First known case of this is in https://github.com/rust-lang/rust/pull/72053#issuecomment-626364402 but may have happened before then.

r? @pietroalbini

graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust