[Bug Report] VueCLI3 Production build Error: 'TypeError: Cannot read property 'isDark' of undefined'

Versions and Environment

Vuetify: 2.0.0-beta.0 Vue: 2.6.10 Browsers: Chrome 74.0.3729.169 OS: Mac OS 10.14.5

Steps to reproduce

• yarn install
• yarn build
• Serve ‘/dist’ folder via http (I have been using https://www.npmjs.com/package/serve)

Expected Behavior

Root page loads without vender bundle errors.

Actual Behavior

v-btns and a link elements fail to load due to error reported in the console:

vue.runtime.esm.js:1888 TypeError: Cannot set property 'isDark' of undefined
    at a.handler (index.js:87)
    at a.t.$watch (vue.runtime.esm.js:4943)
    at yr (vue.runtime.esm.js:4900)
    at mr (vue.runtime.esm.js:4882)
    at or (vue.runtime.esm.js:4642)
    at a.t._init (vue.runtime.esm.js:5000)
    at new a (vue.runtime.esm.js:5148)
    at on (vue.runtime.esm.js:3283)
    at init (vue.runtime.esm.js:3114)
    at d (vue.runtime.esm.js:5972)

Reproduction Link

https://github.com/jvanst/requestly

Other comments

This problem only seems to exist when building with NODE_ENV = production (yarn build). Building the project with the mode flagged as development works fine, use yarn build-dev

[jvanst]

Thanks again for taking a look. I was able to resolve this by removing some bad code, but I still have no idea why it was an issue in production mode and not development.

[daneren2005]

Thanks a lot for your detailed report. The strange thing in our case is that it only happens to a subset of our users. We can not reproduce it, which makes it very hard to track down. Maybe upgrading to Vuetify 2 will make it go away. 😉

Any chance did you ever find a work around for this? We are also only having it happen to end users randomly. Nothing we can do on our end reproduces it, even on the same production builds. We are using the Vue CLI’s modern build flag, but are having it happen on up to date versions of Chrome so I don’t think it is an old device issue.