Arguments: 
  /usr/local/bin/node /usr/local/Cellar/yarn/1.5.1_1/libexec/bin/yarn.js upgrade-interactive --latest

PATH: 
  ./bin:./node_modules/.bin:/usr/local/opt/go/libexec/bin:/Users/jdickey/bin:/Users/jdickey/.fzf/bin:/Users/jdickey/bin:/Users/jdickey/.config/yarn/global/node_modules/.bin:/opt/X11/bin:/usr/local/MacGPG2/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/Users/jdickey/.config/yarn/global/node_modules/.bin:/Users/jdickey/.cargo/bin

Yarn version: 
  1.5.1

Node version: 
  9.11.1

Platform: 
  darwin x64

npm manifest: 
  {
    "name": "@heroku/linewrap",
    "version": "1.0.0",
    "description": "",
    "main": "linewrap.js",
    "scripts": {
      "test": "echo \"Error: no test specified\" && exit 1"
    },
    "repository": {
      "type": "git",
      "url": "git+https://github.com/heroku/node-linewrap.git"
    },
    "author": "Jeff Dickey",
    "license": "ISC",
    "bugs": {
      "url": "https://github.com/heroku/node-linewrap/issues"
    },
    "homepage": "https://github.com/heroku/node-linewrap#readme"
  }

yarn manifest: 
  No manifest

Lockfile: 
  No lockfile

Trace: 
  Error: No lockfile in this directory. Run `yarn install` to generate one.
      at new MessageError (/usr/local/Cellar/yarn/1.5.1_1/libexec/lib/cli.js:186:110)
      at /usr/local/Cellar/yarn/1.5.1_1/libexec/lib/cli.js:89389:13
      at <anonymous>