ERROR in ./app/javascript/packs/application.js
Module build failed: ReferenceError: Unknown plugin "preval" specified in "/mastodon/.babelrc" at 5, attempted to resolve relative to "/mastodon"
    at /mastodon/node_modules/babel-core/lib/transformation/file/options/option-manager.js:180:17
    at Array.map (native)
    at Function.normalisePlugins (/mastodon/node_modules/babel-core/lib/transformation/file/options/option-manager.js:158:20)
    at OptionManager.mergeOptions (/mastodon/node_modules/babel-core/lib/transformation/file/options/option-manager.js:234:36)
    at OptionManager.init (/mastodon/node_modules/babel-core/lib/transformation/file/options/option-manager.js:368:12)
    at File.initOptions (/mastodon/node_modules/babel-core/lib/transformation/file/index.js:212:65)
    at new File (/mastodon/node_modules/babel-core/lib/transformation/file/index.js:135:24)
    at Pipeline.transform (/mastodon/node_modules/babel-core/lib/transformation/pipeline.js:46:16)
    at transpile (/mastodon/node_modules/babel-loader/lib/index.js:49:20)
    at Object.module.exports (/mastodon/node_modules/babel-loader/lib/index.js:174:20)