Auto merge of #7737 - Mark-Simulacrum:cache-not-mem, r=ehuss
Auto merge of #7737 - Mark-Simulacrum:cache-not-mem, r=ehuss

Read cached output line-by-line

This avoids loading potentially gigabytes of output into memory, which
can cause OOMs.

Fixes #7736.

This does not add a test as I don't really want to generate gigabytes of output (that seems like a bad idea) -- and it's unclear how to test other than by causing OOM on (most) CI systems, and it's unlikely that we'll actually regress here.

tsurai/cargo,rust-lang/cargo,tsurai/cargo,eminence/cargo,tshepang/cargo,rustyhorde/cargo,rust-lang/cargo,eminence/cargo,vojtechkral/cargo,vojtechkral/cargo,nipunn1313/cargo,rust-lang/cargo,tshepang/cargo,tsurai/cargo,nipunn1313/cargo,rustyhorde/cargo,vojtechkral/cargo,vojtechkral/cargo,rustyhorde/cargo,nipunn1313/cargo,eminence/cargo,nipunn1313/cargo,rustyhorde/cargo,tsurai/cargo,tshepang/cargo,tshepang/cargo,tsurai/cargo,rust-lang/cargo,eminence/cargo