{"comment":{"url":"https://api.github.com/repos/alexcrichton/rust/comments/15781954","html_url":"https://github.com/alexcrichton/rust/commit/5961e083e609def2cecae68d27d24ea5cb4cd5b5#commitcomment-15781954","id":15781954,"user":{"login":"alexcrichton","id":64996,"avatar_url":"https://avatars.githubusercontent.com/u/64996?v=3","gravatar_id":"","url":"https://api.github.com/users/alexcrichton","html_url":"https://github.com/alexcrichton","followers_url":"https://api.github.com/users/alexcrichton/followers","following_url":"https://api.github.com/users/alexcrichton/following{/other_user}","gists_url":"https://api.github.com/users/alexcrichton/gists{/gist_id}","starred_url":"https://api.github.com/users/alexcrichton/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/alexcrichton/subscriptions","organizations_url":"https://api.github.com/users/alexcrichton/orgs","repos_url":"https://api.github.com/users/alexcrichton/repos","events_url":"https://api.github.com/users/alexcrichton/events{/privacy}","received_events_url":"https://api.github.com/users/alexcrichton/received_events","type":"User","site_admin":false},"position":240,"line":240,"path":"src/bootstrap/build/compile.rs","commit_id":"5961e083e609def2cecae68d27d24ea5cb4cd5b5","created_at":"2016-01-30T20:54:31Z","updated_at":"2016-01-30T20:54:31Z","body":"This was basically me trying to be defensive about upgrades to cargo and such. Cargo doesn't clean out old build directories, so we're not necessarily generating extra files it's moreso we're not cleaning them out if they're super old.\r\n\r\nFor example if Cargo is updated and the hashing algorithm has been tweaked all the old artifacts won't be used by Cargo, but they'll still be present in pre-existing build directories. We may be able to clear the build directory more aggressively, though."}}