Inform users that their pixi installation is not up to date

[corneliusroemer]

I was completely unaware that my pixi installation was 20 minor versions behind.

Would be nice if you informed users that there's something to update to (and how to do so, i.e. whether brew or self update etc, at least for the major cases)

@corneliusroemer https://github.com/corneliusroemer what pixi version
are you using? I believe this BETA message was

Originally posted by @corneliusroemer in #2557 (comment)

[ruben-arts]

Hey @corneliusroemer,

We've had this request before but it didn't get any extra attention so we closed it again.
#763

I would like to get this more towards a proposal before acting on it. I'm still of the opinion that it could create a lot if annoyances if not executed properly. Could you answer some of the questions in #763

[corneliusroemer]

These are great questions @ruben-arts. Off the top of my head:

• when to show: install is the obvious place, maybe add as well (take inspiration from npm, I think they show on install)
• definitely allow people to disable through config (env variable and pixi configrc etc.)
• if people don't want to update, they can silence it, otherwise people can act on it immediately, so by default I'd just show it for all versions (you could theoretically make it configurable, e.g. if new release out >2 weeks or so, but that seems overkill)
• Could also make it opt-in to start with (activate upgrade hints), rather than opt out (silencing)
• Show self-update command if it's a non-package-managed install, otherwise don't show that hint

Does that make sense? Is there something else?