Steps to Reproduce:
- Load https://en.wikipedia.beta.wmflabs.org/wiki/Special:Search
- Enter a character into the search field
In the JavaScript console the error
TypeError: this.pushPending is not a function
is reported.
This problem happens since rMW8414e3c4d0c2: Update OOUI to v0.31.4 (@Jdforrester-WMF @Volker_E).