{"action":"opened","issue":{"url":"https://api.github.com/repos/lesshint/lesshint/issues/164","repository_url":"https://api.github.com/repos/lesshint/lesshint","labels_url":"https://api.github.com/repos/lesshint/lesshint/issues/164/labels{/name}","comments_url":"https://api.github.com/repos/lesshint/lesshint/issues/164/comments","events_url":"https://api.github.com/repos/lesshint/lesshint/issues/164/events","html_url":"https://github.com/lesshint/lesshint/issues/164","id":143360672,"number":164,"title":"error with 1.5.0","user":{"login":"wareczek","id":1897839,"avatar_url":"https://avatars.githubusercontent.com/u/1897839?v=3","gravatar_id":"","url":"https://api.github.com/users/wareczek","html_url":"https://github.com/wareczek","followers_url":"https://api.github.com/users/wareczek/followers","following_url":"https://api.github.com/users/wareczek/following{/other_user}","gists_url":"https://api.github.com/users/wareczek/gists{/gist_id}","starred_url":"https://api.github.com/users/wareczek/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wareczek/subscriptions","organizations_url":"https://api.github.com/users/wareczek/orgs","repos_url":"https://api.github.com/users/wareczek/repos","events_url":"https://api.github.com/users/wareczek/events{/privacy}","received_events_url":"https://api.github.com/users/wareczek/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-03-24T21:12:23Z","updated_at":"2016-03-24T21:12:23Z","closed_at":null,"body":"```\r\nAn unkown error occured, please file an issue with this info:\r\nTypeError: Cannot read property 'content' of null\r\n    at Object.zeroUnitLinter [as lint] (/usr/lib/node_modules/lesshint/lib/linters/zero_unit.js:19:61)\r\n    at /usr/lib/node_modules/lesshint/lib/linter.js:140:32\r\n    at Array.forEach (native)\r\n    at /usr/lib/node_modules/lesshint/lib/linter.js:126:17\r\n    at Node.traverse (/usr/lib/node_modules/lesshint/node_modules/gonzales-pe/lib/node/basic-node.js:207:5)\r\n    at Node.traverse (/usr/lib/node_modules/lesshint/node_modules/gonzales-pe/lib/node/basic-node.js:212:35)\r\n    at Node.traverse (/usr/lib/node_modules/lesshint/node_modules/gonzales-pe/lib/node/basic-node.js:212:35)\r\n    at Node.traverse (/usr/lib/node_modules/lesshint/node_modules/gonzales-pe/lib/node/basic-node.js:212:35)\r\n    at Object.exports.lint (/usr/lib/node_modules/lesshint/lib/linter.js:125:9)\r\n    at Lesshint.checkString (/usr/lib/node_modules/lesshint/lib/lesshint.js:67:25)\r\n```\r\n\r\nsimple less mixin:\r\n```\r\n.background-image(@bar-width: 160px) {\r\n    border: 1px solid red;\r\n}\r\n```"}}