When running yarn install, you get following warning:
warning "easygettext > @vue/compiler-sfc@3.0.3" has incorrect peer dependency "vue@3.0.3".
But when updating vue from 2.6.14 to 3.0.3, you get version mismatch errors with:
vue-loader and vue-template-compiler
Someone (tm) with the right knowledge needs to take a closer look to fix this
Maybe this link helps fixing it:
https://stackoverflow.com/questions/64868632/vuejs-3-problem-with-vue-template-compiler