A Google font we use (Pacifico) recently had a rather radical redesign to the capital 'L'. As we use this for our product with a name begging with 'L' this caused a rather radical change in the look to our product.
Digging into it, I noticed that the url for the fonts had changed from
fonts.gstatic.com/s/pacifico/v7/Q_Z9mv4hySLTMoMjnk_rCXYhjbSpvc47ee6xR_80Hnw.woff2
to
fonts.gstatic.com/s/pacifico/v8/Q_Z9mv4hySLTMoMjnk_rCXYhjbSpvc47ee6xR_80Hnw.woff2
but that the previous v7 urls still worked. So, for now, I have added hardcoded font references to that version.
Is it possible, though, to instead link to a particular version of a font?
<link href='https://fonts.googleapis.com/css?family=Pacifico' rel='stylesheet' type='text/css'>
So, somehow specify a version in the above link?
I have tried various guesses, such as:
https://fonts.googleapis.com/css?family=Pacifico&version=7
https://fonts.googleapis.com/css?family=Pacifico&version=v7
https://fonts.googleapis.com/css?family=Pacifico:v7
but to no avail.
The recommended way to stick with a particular version is to self-host it.
Google does not and will not have a versioning option.
The API
v7hack you're using is officially not recommended, and may break.A Google Fonts employee “davelab6” has been responding to several questions like yours on the Google Fonts github. This question is much like yours and has a brief answer from him. It also links to several other issues with spirited discussion about a similar change.
The upshot is that Google has considered offering a versioning feature and rejected it for several reasons. They say the vast majority of users will be fine with the latest version of a font, and the rest can self-host the version they like.
As for how to self-host, I'm out of my depth, but there's a question about it here with several answers.