Andy Allan

> unless the `.fmt` support is a hard requirement. Yeah, I pretty much think it's a hard requirement - or at least (as I said above) not doing anything now...

Can the dots in the key be url encoded? E.g. `/user/preference/foo%2Ebar.xml` for the key `foo.bar`?

> Technically, yes. `%2E` is `.`. See [RFC3986](https://www.ietf.org/rfc/rfc3986.txt) section 2.1 for details (_all_ ASCII characters can be URL encoded, syntax is `%`) I was just reading section 2.3 "Unreserved Characters"...

I'm wondering how many preferences, other than the ones in this codebase, use problematic characters from the set `INVALID_URL_CHARS = "/;.,?%#".freeze`, and what it would take to migrate in order...

I don't understand what you are trying to achieve with the "multiple `.` problem" - can you explain it further? Dropping the `resources` and moving to hand-crafted routes is a...

> The problem is that `user/preferences/gps.trace.visibility` will lead to a routing error (it cannot find the route) if `resources` is used. But I still don't understand what you are trying...

@ZhengLin-Li yes, this still needs to be fixed. You are welcome to work on fixing this!

Fixed by #3864

There's two different issues discussed here, and while they are related they are not the same. `bundle exec rails yarn:install` failing to find yarn on Ubuntu is not the same...

> I think that newer versions of yarn have dropped support for `--ignore-engines` haven't they, which is the main reason our old approach of using a wrapper no longer worked...