I solved this problem! I was specifying this in quasar.conf.js to fix some routing issues that I was seeing when running “quasar dev” : extendWebpack(cfg) { cfg.output = { publicPath: "/", }; } cfg.output was not set when running “quasar dev” but it is set when running “quasar build -m cordova -T ios” and so I was inadvertently overwriting it. Changing it to this let me get further: extendWebpack(cfg) { if (!cfg.output) { cfg.output = { publicPath: "/", }; } }

If you are interested in updating to Babel 7.x (which I have done), there is a great tool here: https://github.com/babel/babel-upgrade