{"action":"closed","issue":{"url":"https://api.github.com/repos/fsharp/fsharp/issues/311","labels_url":"https://api.github.com/repos/fsharp/fsharp/issues/311/labels{/name}","comments_url":"https://api.github.com/repos/fsharp/fsharp/issues/311/comments","events_url":"https://api.github.com/repos/fsharp/fsharp/issues/311/events","html_url":"https://github.com/fsharp/fsharp/issues/311","id":34261831,"number":311,"title":"FS0193 on deb/ubuntu package but fine on same version compiled from source","user":{"login":"cdrnet","id":47147,"avatar_url":"https://avatars.githubusercontent.com/u/47147?v=3","gravatar_id":"","url":"https://api.github.com/users/cdrnet","html_url":"https://github.com/cdrnet","followers_url":"https://api.github.com/users/cdrnet/followers","following_url":"https://api.github.com/users/cdrnet/following{/other_user}","gists_url":"https://api.github.com/users/cdrnet/gists{/gist_id}","starred_url":"https://api.github.com/users/cdrnet/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/cdrnet/subscriptions","organizations_url":"https://api.github.com/users/cdrnet/orgs","repos_url":"https://api.github.com/users/cdrnet/repos","events_url":"https://api.github.com/users/cdrnet/events{/privacy}","received_events_url":"https://api.github.com/users/cdrnet/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":5,"created_at":"2014-05-25T12:23:50Z","updated_at":"2015-03-22T00:42:57Z","closed_at":"2015-03-22T00:42:57Z","body":"I observe a weird issue where modifying a record\r\n\r\n    let q = { p with Version = \"1.2.3\" }\r\n\r\nfails with\r\n\r\n    error FS0193: internal error: Argument cannot be null.\r\n    Parameter name: obj\r\n\r\nSee original ticket fsharp/FAKE#436.\r\n\r\nThis error only happens when I use the official packages delivered by apt-get on current Ubuntu 14.04 LTS:\r\n\r\n* mono-complete 3.2.8+dfsg-4ubuntu1\r\n* fsharp 3.0.34+dfsg-3ubuntu1\r\n\r\nBut it works fine when compiling and installing the following tags from source on the same machine:\r\n\r\n* mono: mono-3.2.8\r\n* fsharp: 3.0.34\r\n\r\nIt also works fine on .Net/Windows."}}