How to download/install a bottle for the old version supporting Mojave?

[volo-droid]

Is there a way to download or install one of the previous versions of scrcpy formula bottles that supports Mojave?
On Mojave the latest version of scrcpy formula is built from the sources, and installing a rust dependency takes ages to complete. GitHub packages contain previous version bottles that have binaries for Mojave. For example:
https://github.com/Homebrew/homebrew-core/pkgs/container/core%2Fscrcpy/9705995?tag=1.19

How could I install or extract those binaries?

[SMillerDev]

Since Mojave is no longer supported by Apple we dropped support for it too, this is why it's building from source. The best solution would be to update your OS so you can use bottles again.

If you want the latest version of scrcpy I'm afraid you'll always have to build from source on Mojave since the latest dependencies are no longer available for Mojave either. If you're fine installing any version you could check when the latest mojave bottle was available and download that version from the GitHub package registry. How to do that I'm not sure, it's some magic with docker formats

[volo-droid]

@SMillerDev thanks for quick the answer! Is there any reason why brew doesn't have a feature to install an old version from the GitHub registry? (i.e. nobody requested it, or it goes against the philosophy of brew etc). I mean, the binaries are there so I'd assume it's not a big difference to fetch a specific version instead of the latest one.

[carlocab]

It's mostly against our philosophy -- we're a rolling release package manager. Trying to do what you're doing is a bit fragile and easily causes breakage for other formulae you have installed, which is another reason why we don't give users ways to do this easily. Note that Homebrew is built on Git, though, so knowing Git should be all you need to do what you want to do. (I'll refrain from spelling out the steps further for reasons already discussed.)

[fmillion-mnsu]

Out of curiosity, has there ever been any thought given to "locking" the last versions of packages currently supported before deprecating an older OS? For example, "if you want prebuilt bottles, this is the version you get from now on...if you want to go newer, you're on your own and you'll be building from source". I'd imagine something like Git branching could do this - admittedly I haven't looked into how the repos are set up yet, but was just a passing thought.

There's lots of reasons people might be stuck on an older OS - unsupported machine, some other app that isn't and won't be updated, a major feature the user depends on was changed in a breaking way in the new OS, etc. Apple of course deprecates their support pretty quickly, which is why I was thinking of "ok, we were supported up until today, so unless you add a flag like --newest or something, you get these specific bottles...and that's it, we won't be building/hosting any new ones." A lot of times these older machines and OSes are being kept around for purpose-specific needs and "the latest version" isn't always a necessity.

I can understand the potential cost issue of hosting binary blobs for older OS'es, but that might be where some kind of community support might need to step in.

[SMillerDev]

It's hard maintaining just the OS versions Apple supports with the small team Homebrew has, adding more OS versions that are not supported by Apple is not something that would be worth the effort in my book.

[volo-droid]

In the end I was able to do it with oras.
The following comments from one of brew maintainers provide valuable info on how bottles are stored and can be accessed: oras-project/oras#237 (comment)

[fuji246]

Could you share the command? thanks!

[volo-droid]

@fuji246 have a look at the comment here: oras-project/oras#237 (comment)

oras pull ghcr.io/homebrew/core/hello:2.10