message: Add check in build script that tweego was installed
diff: /* eslint-disable @typescript-eslint/no-var-requires */
  +const fs = require('fs')
  const path = require('path')
  const spawn = require('child_process').spawn
  const utils = require('./utils')
  @@ -7,6 +8,12 @@ const webpack = require('webpack')
  utils.logClear()
  const tweego = path.resolve(utils.twineFolder, 'tweego')
  +if (!fs.existsSync(tweego)) {
  + utils.logError('Cannot find path to tweego.')
  + utils.logError('Perhaps tweego has not been downloaded.')
  + utils.logError('Try running `yarn install-compiler` first.')
  + process.exit(1)
  +}
  // Extract extra arguments.
  const [, , ...flags] = process.argv
  